Windows UAC Bypass Suspicious Escalation Behavior: endpointEndpointrisk_score:642024-11-28version:4
The following analytic detects when a process spawns an executable known for User Account Control (UAC) bypass exploitation and subsequently monitors for any child processes with a higher integrity level than the original process. This detection leverages Sysmon EventID 1 data, focusing on process integrity levels and known UAC bypass executables. This activity is significant as it may indicate an attacker has successfully used a UAC bypass exploit to escalate privileges. If confirmed malicious, the attacker could gain elevated privileges, potentially leading to further system compromise and persistent access.
NET Profiler UAC bypass: endpointEndpointrisk_score:632024-09-30version:4
The following analytic detects modifications to the registry aimed at bypassing the User Account Control (UAC) feature in Windows. It identifies changes to the .NET COR_PROFILER_PATH registry key, which can be exploited to load a malicious DLL via mmc.exe. This detection leverages data from the Endpoint.Registry datamodel, focusing on specific registry paths and values. Monitoring this activity is crucial as it can indicate an attempt to escalate privileges or persist within the environment. If confirmed malicious, this could allow an attacker to execute arbitrary code with elevated privileges, compromising system integrity.
Windows Impair Defense Disable Win Defender Scan On Update: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable the Windows Defender Scan On Update feature. It leverages data from the Endpoint.Registry datamodel, specifically looking for changes to the "DisableScanOnUpdate" registry setting with a value of "0x00000001". This activity is significant because disabling automatic scans can leave systems vulnerable to malware and other threats. If confirmed malicious, this action could allow attackers to bypass Windows Defender, facilitating further compromise and persistence within the environment.
Windows Impair Defense Override SmartScreen Prompt: endpointEndpointrisk_score:492024-11-14version:4
The following analytic detects modifications to the Windows registry that override the Windows Defender SmartScreen prompt. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the "PreventSmartScreenPromptOverride" registry setting. This activity is significant because it indicates an attempt to disable the prevention of user overrides for SmartScreen prompts, potentially allowing users to bypass security warnings. If confirmed malicious, this could lead to users inadvertently executing or accessing harmful content, increasing the risk of security incidents or system compromises.
Windows Disable Change Password Through Registry: endpointEndpointrisk_score:492024-12-08version:7
The following analytic detects a suspicious registry modification that disables the Change Password feature on a Windows host. It identifies changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableChangePassword" with a value of "0x00000001". This activity is significant as it can prevent users from changing their passwords, a tactic often used by ransomware to maintain control over compromised systems. If confirmed malicious, this could hinder user response to an attack, allowing the attacker to persist and potentially escalate their access within the network.
Windows Impair Defense Overide Win Defender Phishing Filter: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable the Windows Defender phishing filter. It leverages data from the Endpoint.Registry data model, focusing on changes to specific registry values related to Microsoft Edge's phishing filter settings. This activity is significant because disabling the phishing filter can allow attackers to deceive users into visiting malicious websites without triggering browser warnings. If confirmed malicious, this could lead to users unknowingly accessing harmful sites, resulting in potential security incidents or data compromises.
Windows Defender Exclusion Registry Entry: endpointEndpointrisk_score:642024-12-08version:8
The following analytic detects modifications to the Windows Defender exclusion registry entries. It leverages endpoint registry data to identify changes in the registry path "*\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Exclusions\\*". This activity is significant because adversaries often modify these entries to bypass Windows Defender, allowing malicious code to execute without detection. If confirmed malicious, this behavior could enable attackers to evade antivirus defenses, maintain persistence, and execute further malicious activities undetected.
Windows Parent PID Spoofing with Explorer: endpointEndpointrisk_score:642024-11-28version:4
The following analytic identifies a suspicious `explorer.exe` process with the `/root` command-line parameter. This detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process and command-line data. The presence of `/root` in `explorer.exe` is significant as it may indicate parent process spoofing, a technique used by malware to evade detection. If confirmed malicious, this activity could allow an attacker to operate undetected, potentially leading to unauthorized access, privilege escalation, or persistent threats within the environment.
Windows Disable Notification Center: endpointEndpointrisk_score:482024-12-08version:7
The following analytic detects the modification of the Windows registry to disable the Notification Center on a host machine. It leverages data from the Endpoint.Registry data model, specifically looking for changes to the "DisableNotificationCenter" registry value set to "0x00000001." This activity is significant because disabling the Notification Center can be a tactic used by RAT malware to hide its presence and subsequent actions. If confirmed malicious, this could allow an attacker to operate stealthily, potentially leading to further system compromise and data exfiltration.
Windows Impair Defense Disable Win Defender Report Infection: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable Windows Defender's infection reporting. It leverages data from the Endpoint.Registry datamodel, specifically monitoring changes to the "DontReportInfectionInformation" registry key. This activity is significant because it can prevent Windows Defender from reporting detailed threat information to Microsoft, potentially allowing malware to evade detection. If confirmed malicious, this action could enable attackers to bypass security measures, maintain persistence, and avoid detection, leading to prolonged unauthorized access and potential data breaches.
Windows DisableAntiSpyware Registry: endpointEndpointrisk_score:242024-09-30version:4
The following analytic detects the modification of the Windows Registry key "DisableAntiSpyware" being set to disable. This detection leverages data from the Endpoint.Registry datamodel, specifically looking for the registry value name "DisableAntiSpyware" with a value of "0x00000001". This activity is significant as it is commonly associated with Ryuk ransomware infections, indicating potential malicious intent to disable Windows Defender. If confirmed malicious, this action could allow attackers to disable critical security defenses, facilitating further malicious activities such as data encryption, exfiltration, or additional system compromise.
Windows Disable Windows Event Logging Disable HTTP Logging: endpointEndpointrisk_score:642024-11-28version:5
The following analytic detects the use of AppCmd.exe to disable HTTP logging on IIS servers. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution events where AppCmd.exe is used with specific parameters to alter logging settings. This activity is significant because disabling HTTP logging can help adversaries hide their tracks and avoid detection by removing evidence of their actions. If confirmed malicious, this could allow attackers to operate undetected, making it difficult to trace their activities and respond to the intrusion effectively.
Windows PowerShell Disable HTTP Logging: endpointEndpointrisk_score:642024-09-30version:3
The following analytic detects the use of `get-WebConfigurationProperty` and `Set-ItemProperty` commands in PowerShell to disable HTTP logging on Windows systems. This detection leverages PowerShell Script Block Logging, specifically looking for script blocks that reference HTTP logging properties and attempt to set them to "false" or "dontLog". Disabling HTTP logging is significant as it can be used by adversaries to cover their tracks and delete logs, hindering forensic investigations. If confirmed malicious, this activity could allow attackers to evade detection and persist in the environment undetected.
Windows Impair Defense Disable Controlled Folder Access: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects a modification in the Windows registry that disables the Windows Defender Controlled Folder Access feature. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the EnableControlledFolderAccess registry setting. This activity is significant because Controlled Folder Access is designed to protect critical folders from unauthorized access, including ransomware attacks. If this activity is confirmed malicious, it could allow attackers to bypass a key security feature, potentially leading to unauthorized access or modification of sensitive files.
Windows Alternate DataStream - Process Execution: endpointEndpointrisk_score:802024-11-28version:4
The following analytic detects when a process attempts to execute a file from within an NTFS file system alternate data stream. This detection leverages process execution data from sources like Windows process monitoring or Sysmon Event ID 1, focusing on specific processes known for such behavior. This activity is significant because alternate data streams can be used by threat actors to hide malicious code, making it difficult to detect. If confirmed malicious, this could allow an attacker to execute hidden code, potentially leading to unauthorized actions and further compromise of the system.
Windows LOLBAS Executed Outside Expected Path: endpointEndpointrisk_score:402024-09-30version:2
The following analytic identifies a LOLBAS process being executed outside of it's expected location. Processes being executed outside of expected locations may be an indicator that an adversary is attempting to evade defenses or execute malicious code. The LOLBAS project documents Windows native binaries that can be abused by threat actors to perform tasks like executing malicious code.
Windows Impair Defense Delete Win Defender Context Menu: endpointEndpointrisk_score:252024-10-17version:3
The following analytic detects the deletion of the Windows Defender context menu entry from the registry. It leverages data from the Endpoint datamodel, specifically monitoring registry actions where the path includes "*\\shellex\\ContextMenuHandlers\\EPP" and the action is 'deleted'. This activity is significant as it is commonly associated with Remote Access Trojan (RAT) malware attempting to disable security features. If confirmed malicious, this could allow an attacker to impair defenses, facilitating further malicious activities such as unauthorized access, persistence, and data exfiltration.
Disable Security Logs Using MiniNt Registry: endpointEndpointrisk_score:802024-12-08version:8
The following analytic detects a suspicious registry modification aimed at disabling security audit logs by adding a specific registry entry. It leverages data from the Endpoint.Registry data model, focusing on changes to the "Control\\MiniNt" registry path. This activity is significant because it can prevent Windows from logging any events to the Security Log, effectively blinding security monitoring efforts. If confirmed malicious, this technique could allow an attacker to operate undetected, making it difficult to trace their actions and compromising the integrity of security audits.
Windows UAC Bypass Suspicious Child Process: endpointEndpointrisk_score:452024-09-30version:3
The following analytic detects when an executable known for User Account Control (UAC) bypass exploitation spawns a child process in a user-controlled location or a command shell executable (e.g., cmd.exe, powershell.exe). This detection leverages Sysmon EventID 1 data, focusing on high or system integrity level processes with specific parent-child process relationships. This activity is significant as it may indicate an attacker has successfully used a UAC bypass exploit to escalate privileges. If confirmed malicious, this could allow the attacker to execute arbitrary commands with elevated privileges, potentially compromising the entire system.
Disabling Windows Local Security Authority Defences via Registry: endpointEndpointrisk_score:602024-09-30version:4
The following analytic identifies the deletion of registry keys that disable Local Security Authority (LSA) protection and Microsoft Defender Device Guard. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry actions and paths associated with LSA and Device Guard settings. This activity is significant because disabling these defenses can leave a system vulnerable to various attacks, including credential theft and unauthorized code execution. If confirmed malicious, this action could allow attackers to bypass critical security mechanisms, leading to potential system compromise and persistent access.
Windows Impair Defense Change Win Defender Health Check Intervals: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that change the health check interval of Windows Defender. It leverages data from the Endpoint datamodel, specifically monitoring changes to the "ServiceKeepAlive" registry path with a value of "0x00000001". This activity is significant because altering Windows Defender settings can impair its ability to perform timely health checks, potentially leaving the system vulnerable. If confirmed malicious, this could allow an attacker to disable or delay security scans, increasing the risk of undetected malware or other malicious activities.
Windows Registry Dotnet ETW Disabled Via ENV Variable: endpointEndpointrisk_score:902024-12-08version:1
The following analytic detects a registry modification that disables the ETW for the .NET Framework. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the COMPlus_ETWEnabled registry value under the "Environment" registry key path for both user (HKCU\Environment) and machine (HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment) scopes. This activity is significant because disabling ETW can allow attackers to evade Endpoint Detection and Response (EDR) tools and hide their execution from audit logs. If confirmed malicious, this action could enable attackers to operate undetected, potentially leading to further compromise and persistent access within the environment.
SilentCleanup UAC Bypass: endpointEndpointrisk_score:632024-09-30version:5
The following analytic detects suspicious modifications to the registry that may indicate a UAC (User Account Control) bypass attempt via the SilentCleanup task. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry changes in the path "*\\Environment\\windir" with executable values. This activity is significant as it can allow an attacker to gain high-privilege execution without user consent, bypassing UAC protections. If confirmed malicious, this could lead to unauthorized administrative access, enabling further system compromise and persistence.
Windows Command and Scripting Interpreter Path Traversal Exec: endpointEndpointrisk_score:902024-11-28version:5
The following analytic detects path traversal command-line execution, often used in malicious documents to execute code via msdt.exe for defense evasion. It leverages Endpoint Detection and Response (EDR) data, focusing on specific patterns in process paths. This activity is significant as it can indicate an attempt to bypass security controls and execute unauthorized code. If confirmed malicious, this behavior could lead to code execution, privilege escalation, or persistence within the environment, potentially allowing attackers to deploy malware or leverage other living-off-the-land binaries (LOLBins).
Windows Disable Windows Group Policy Features Through Registry: endpointEndpointrisk_score:492024-12-08version:7
The following analytic detects suspicious registry modifications aimed at disabling Windows Group Policy features. It leverages data from the Endpoint.Registry data model, focusing on specific registry paths and values associated with disabling key Windows functionalities. This activity is significant because it is commonly used by ransomware to hinder mitigation and forensic response efforts. If confirmed malicious, this behavior could severely impair the ability of security teams to analyze and respond to the attack, allowing the attacker to maintain control and persist within the compromised environment.
Windows Impair Defense Delete Win Defender Profile Registry: endpointEndpointrisk_score:642024-09-30version:3
The following analytic detects the deletion of the Windows Defender main profile registry key. It leverages data from the Endpoint.Registry datamodel, specifically monitoring for deleted actions within the Windows Defender registry path. This activity is significant as it indicates potential tampering with security defenses, often associated with Remote Access Trojans (RATs) and other malware. If confirmed malicious, this action could allow an attacker to disable Windows Defender, reducing the system's ability to detect and respond to further malicious activities, thereby compromising endpoint security.
Disable Windows SmartScreen Protection: endpointEndpointrisk_score:252024-12-08version:9
The following analytic detects modifications to the Windows registry that disable SmartScreen protection. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with SmartScreen settings. This activity is significant because SmartScreen provides an early warning system against phishing and malware. Disabling it can indicate malicious intent, often seen in Remote Access Trojans (RATs) to evade detection while downloading additional payloads. If confirmed malicious, this action could allow attackers to bypass security measures, increasing the risk of successful phishing attacks and malware infections.
Windows Alternate DataStream - Base64 Content: endpointEndpointrisk_score:802024-09-30version:4
The following analytic detects the creation of Alternate Data Streams (ADS) with Base64 content on Windows systems. It leverages Sysmon EventID 15, which captures file creation events, including the content of named streams. ADS can conceal malicious payloads, making them significant for SOC monitoring. This detection identifies hidden streams that may contain executables, scripts, or configuration data, often used by malware to evade detection. If confirmed malicious, this activity could allow attackers to hide and execute payloads, persist in the environment, or access sensitive information without being easily detected.
Disabling Firewall with Netsh: endpointEndpointrisk_score:252024-09-30version:5
The following analytic identifies the disabling of the firewall using the netsh application. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that include keywords like "firewall," "off," or "disable." This activity is significant because disabling the firewall can expose the system to external threats, allowing malware to communicate with its command and control (C2) server. If confirmed malicious, this action could lead to unauthorized data exfiltration, further malware downloads, and broader network compromise.
Disabling ControlPanel: endpointEndpointrisk_score:252024-12-08version:9
The following analytic detects registry modifications that disable the Control Panel on Windows systems. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\NoControlPanel" with a value of "0x00000001". This activity is significant as it is commonly used by malware to prevent users from accessing the Control Panel, thereby hindering the removal of malicious artifacts and persistence mechanisms. If confirmed malicious, this could allow attackers to maintain control over the infected machine and prevent remediation efforts.
Hiding Files And Directories With Attrib exe: endpointEndpointrisk_score:722024-11-28version:8
The following analytic detects the use of the Windows binary attrib.exe to hide files or directories by marking them with specific flags. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line arguments that include the "+h" flag. This activity is significant because hiding files can be a tactic used by attackers to conceal malicious files or tools from users and security software. If confirmed malicious, this behavior could allow an attacker to persist in the environment undetected, potentially leading to further compromise or data exfiltration.
Disable Show Hidden Files: endpointEndpointrisk_score:402024-12-08version:9
The following analytic detects modifications to the Windows registry that disable the display of hidden files. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with hidden file settings. This activity is significant because malware, such as worms and trojan spyware, often use hidden files to evade detection. If confirmed malicious, this behavior could allow an attacker to conceal malicious files on the system, making it harder for security tools and analysts to identify and remove the threat.
Windows Rasautou DLL Execution: endpointEndpointrisk_score:802024-11-28version:5
The following analytic detects the execution of an arbitrary DLL by the Windows Remote Auto Dialer (rasautou.exe). This behavior is identified by analyzing process creation events where rasautou.exe is executed with specific command-line arguments. This activity is significant because it leverages a Living Off The Land Binary (LOLBin) to execute potentially malicious code, bypassing traditional security controls. If confirmed malicious, this technique could allow an attacker to execute arbitrary code, potentially leading to system compromise, privilege escalation, or persistent access within the environment.
Windows Impair Defense Define Win Defender Threat Action: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows Defender ThreatSeverityDefaultAction registry setting. It leverages data from the Endpoint.Registry datamodel to identify changes in registry values that define how Windows Defender responds to threats. This activity is significant because altering these settings can impair the system's defense mechanisms, potentially allowing threats to go unaddressed. If confirmed malicious, this could enable attackers to bypass antivirus protections, leading to persistent threats and increased risk of data compromise or further system exploitation.
Windows Impair Defense Disable Win Defender Signature Retirement: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable Windows Defender Signature Retirement. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the DisableSignatureRetirement registry setting. This activity is significant because disabling signature retirement can prevent Windows Defender from removing outdated antivirus signatures, potentially reducing its effectiveness in detecting threats. If confirmed malicious, this action could allow an attacker to evade detection by using older, less relevant signatures, thereby compromising the system's security posture.
Windows Impair Defenses Disable Win Defender Auto Logging: endpointEndpointrisk_score:242024-12-09version:4
The following analytic detects the disabling of Windows Defender logging by identifying changes to the Registry keys DefenderApiLogger or DefenderAuditLogger set to disable. It leverages data from the Endpoint.Registry datamodel to monitor specific registry paths and values. This activity is significant as it is commonly associated with Remote Access Trojan (RAT) malware attempting to evade detection. If confirmed malicious, this action could allow an attacker to conceal their activities, making it harder to detect further malicious actions and maintain persistence on the compromised endpoint.
Add or Set Windows Defender Exclusion: endpointEndpointrisk_score:642024-11-28version:5
The following analytic detects the use of commands to add or set exclusions in Windows Defender. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving "Add-MpPreference" or "Set-MpPreference" with exclusion parameters. This activity is significant because adversaries often use it to bypass Windows Defender, allowing malicious code to execute undetected. If confirmed malicious, this behavior could enable attackers to evade antivirus detection, maintain persistence, and execute further malicious activities without interference from Windows Defender.
Excessive number of service control start as disabled: endpointEndpointrisk_score:802024-09-30version:4
The following analytic detects an excessive number of `sc.exe` processes launched with the command line argument `start= disabled` within a short period. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, command-line executions, and process GUIDs. This activity is significant as it may indicate an attempt to disable critical services, potentially impairing system defenses. If confirmed malicious, this behavior could allow an attacker to disrupt security mechanisms, hinder incident response, and maintain control over the compromised system.
Windows Impair Defense Change Win Defender Quick Scan Interval: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that change the Windows Defender Quick Scan Interval. It leverages data from the Endpoint.Registry data model, focusing on changes to the "QuickScanInterval" registry path. This activity is significant because altering the scan interval can impair Windows Defender's ability to detect malware promptly, potentially allowing threats to persist undetected. If confirmed malicious, this modification could enable attackers to bypass security measures, maintain persistence, and execute further malicious activities without being detected by quick scans.
Disable Windows Behavior Monitoring: endpointEndpointrisk_score:402024-12-08version:10
The following analytic identifies modifications in the registry to disable Windows Defender's real-time behavior monitoring. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with Windows Defender settings. This activity is significant because disabling real-time protection is a common tactic used by malware such as RATs, bots, or Trojans to evade detection. If confirmed malicious, this action could allow an attacker to execute code, escalate privileges, or persist in the environment without being detected by antivirus software.
Windows DLL Search Order Hijacking Hunt: endpointEndpointrisk_score:12024-10-17version:4
The following hunting analytic is an experimental query built against a accidental feature using the latest Sysmon TA 3.0 (https://splunkbase.splunk.com/app/5709/) which maps the module load (ImageLoaded) to process_name. This analytic will deprecate once this is fixed. This hunting analytic identifies known libraries in Windows that may be used in a DLL search order hijack or DLL Sideloading setting. This may require recompiling the DLL, moving the DLL or moving the vulnerable process. The query looks for any running out of system32 or syswow64. Some libraries natively run out of other application paths and will need to be added to the exclusion as needed. The lookup is comprised of Microsoft native libraries identified within the Hijacklibs.net project.
Windows DLL Search Order Hijacking Hunt with Sysmon: endpointEndpointrisk_score:12024-10-17version:6
The following analytic identifies potential DLL search order hijacking or DLL sideloading by detecting known Windows libraries loaded from non-standard directories. It leverages Sysmon EventCode 7 to monitor DLL loads and cross-references them with a lookup of known hijackable libraries. This activity is significant as it may indicate an attempt to execute malicious code by exploiting DLL search order vulnerabilities. If confirmed malicious, this could allow attackers to gain code execution, escalate privileges, or maintain persistence within the environment.
UAC Bypass MMC Load Unsigned Dll: endpointEndpointrisk_score:632024-09-30version:3
The following analytic detects the loading of an unsigned DLL by the MMC.exe application, which is indicative of a potential UAC bypass or privilege escalation attempt. It leverages Sysmon EventCode 7 to identify instances where MMC.exe loads a non-Microsoft, unsigned DLL. This activity is significant because attackers often use this technique to modify CLSID registry entries, causing MMC.exe to load malicious DLLs, thereby bypassing User Account Control (UAC) and gaining elevated privileges. If confirmed malicious, this could allow an attacker to execute arbitrary code with higher privileges, leading to further system compromise and persistence.
Disabling FolderOptions Windows Feature: endpointEndpointrisk_score:252024-12-08version:9
The following analytic detects the modification of the Windows registry to disable the Folder Options feature, which prevents users from showing hidden files and file extensions. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\NoFolderOptions" with a value of "0x00000001". This activity is significant as it is commonly used by malware to conceal malicious files and deceive users with fake file extensions. If confirmed malicious, this could allow an attacker to hide their presence and malicious files, making detection and remediation more difficult.
Windows Impair Defense Disable Defender Firewall And Network: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications in the Windows registry to disable firewall and network protection settings within Windows Defender Security Center. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the UILockdown registry value. This activity is significant as it may indicate an attempt to impair system defenses, potentially restricting users from modifying firewall or network protection settings. If confirmed malicious, this could allow an attacker to weaken the system's security posture, making it more vulnerable to further attacks and unauthorized access.
Windows DISM Remove Defender: accessEndpointrisk_score:802024-11-28version:5
The following analytic detects the use of `dism.exe` to remove Windows Defender. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions that include specific parameters for disabling and removing Windows Defender. This activity is significant because adversaries may disable Defender to evade detection and carry out further malicious actions undetected. If confirmed malicious, this could lead to the attacker gaining persistent access, executing additional payloads, or exfiltrating sensitive data without being intercepted by Windows Defender.
SLUI Spawning a Process: endpointEndpointrisk_score:632024-11-28version:4
The following analytic detects the Microsoft Software Licensing User Interface Tool (`slui.exe`) spawning a child process. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process creation events where `slui.exe` is the parent process. This activity is significant because `slui.exe` should not typically spawn child processes, and doing so may indicate a UAC bypass attempt, leading to elevated privileges. If confirmed malicious, an attacker could leverage this to execute code with elevated privileges, potentially compromising the system's security and gaining unauthorized access.
WSReset UAC Bypass: endpointEndpointrisk_score:632024-09-30version:5
The following analytic detects a suspicious modification of the registry aimed at bypassing User Account Control (UAC) by leveraging WSReset.exe. It identifies the creation or modification of specific registry values under the path "*\\AppX82a6gwre4fdg3bt635tn5ctqjf8msdd2\\Shell\\open\\command*". This detection uses data from Endpoint Detection and Response (EDR) agents, focusing on process and registry events. This activity is significant because UAC bypass techniques can allow attackers to execute high-privilege actions without user consent. If confirmed malicious, this could lead to unauthorized code execution and potential system compromise.
Windows Impair Defense Disable Win Defender Network Protection: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable Windows Defender Network Protection. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the EnableNetworkProtection registry entry. This activity is significant because disabling Network Protection can leave the system vulnerable to network-based threats by preventing Windows Defender from analyzing and blocking malicious network activity. If confirmed malicious, this action could allow attackers to bypass security measures, potentially leading to unauthorized access, data exfiltration, or further compromise of the network.
Windows Impair Defense Disable Win Defender App Guard: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable Windows Defender Application Guard auditing. It leverages data from the Endpoint.Registry data model, focusing on specific registry paths and values. This activity is significant because disabling auditing can hinder security monitoring and threat detection within the isolated environment, making it easier for malicious activities to go unnoticed. If confirmed malicious, this action could allow attackers to bypass Windows Defender protections, potentially leading to unauthorized access, data exfiltration, or further system compromise.
SLUI RunAs Elevated: endpointEndpointrisk_score:632024-11-28version:4
The following analytic detects the execution of the Microsoft Software Licensing User Interface Tool (`slui.exe`) with elevated privileges using the `-verb runas` function. This activity is identified through logs from Endpoint Detection and Response (EDR) agents, focusing on specific registry keys and command-line parameters. This behavior is significant as it indicates a potential privilege escalation attempt, which could allow an attacker to gain elevated access and execute malicious actions with higher privileges. If confirmed malicious, this could lead to unauthorized system changes, data exfiltration, or further compromise of the affected endpoint.
Powershell Windows Defender Exclusion Commands: endpointEndpointrisk_score:642024-09-30version:5
The following analytic detects the use of PowerShell commands to add or set Windows Defender exclusions. It leverages EventCode 4104 to identify suspicious `Add-MpPreference` or `Set-MpPreference` commands with exclusion parameters. This activity is significant because adversaries often use it to bypass Windows Defender, allowing malicious code to execute without detection. If confirmed malicious, this behavior could enable attackers to evade antivirus defenses, maintain persistence, and execute further malicious activities undetected.
FodHelper UAC Bypass: endpointEndpointrisk_score:812024-11-28version:6
The following analytic detects the execution of fodhelper.exe, which is known to exploit a User Account Control (UAC) bypass by leveraging specific registry keys. The detection method uses Endpoint Detection and Response (EDR) telemetry to identify when fodhelper.exe spawns a child process and accesses the registry keys. This activity is significant because it indicates a potential privilege escalation attempt by an attacker. If confirmed malicious, the attacker could execute commands with elevated privileges, leading to unauthorized system changes and potential full system compromise.
Windows Impair Defense Disable Win Defender Gen reports: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications in the Windows registry to disable Windows Defender generic reports. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the "DisableGenericRePorts" registry value. This activity is significant as it can prevent the transmission of error reports to Microsoft's Windows Error Reporting service, potentially hiding malicious activities. If confirmed malicious, this action could allow attackers to bypass Windows Defender detections, reducing the visibility of their activities and increasing the risk of undetected system compromise.
Disable UAC Remote Restriction: endpointEndpointrisk_score:802024-12-08version:8
The following analytic detects the modification of the registry to disable UAC remote restriction by setting the "LocalAccountTokenFilterPolicy" value to "0x00000001". It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\CurrentVersion\\Policies\\System*". This activity is significant because disabling UAC remote restriction can allow an attacker to bypass User Account Control (UAC) protections, potentially leading to privilege escalation. If confirmed malicious, this could enable an attacker to execute unauthorized actions with elevated privileges, compromising the security of the affected system.
Firewall Allowed Program Enable: endpointEndpointrisk_score:252024-09-30version:3
The following analytic detects the modification of a firewall rule to allow the execution of a specific application. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events with command-line arguments related to firewall rule changes. This activity is significant as it may indicate an attempt to bypass firewall restrictions, potentially allowing unauthorized applications to communicate over the network. If confirmed malicious, this could enable an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the target environment.
Windows Event For Service Disabled: endpointEndpointrisk_score:362024-10-17version:5
The following analytic detects when a Windows service is modified from a start type to disabled. It leverages system event logs, specifically EventCode 7040, to identify this change. This activity is significant because adversaries often disable security or other critical services to evade detection and maintain control over a compromised host. If confirmed malicious, this action could allow attackers to bypass security defenses, leading to further exploitation and persistence within the environment.
Eventvwr UAC Bypass: endpointEndpointrisk_score:802024-09-30version:6
The following analytic detects an Eventvwr UAC bypass by identifying suspicious registry modifications in the path that Eventvwr.msc references upon execution. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry changes and process execution details. This activity is significant because it indicates a potential privilege escalation attempt, allowing an attacker to execute arbitrary commands with elevated privileges. If confirmed malicious, this could lead to unauthorized code execution, persistence, and further compromise of the affected system.
Windows Alternate DataStream - Executable Content: endpointEndpointrisk_score:802024-09-30version:4
The following analytic detects the writing of data with an IMPHASH value to an Alternate Data Stream (ADS) in the NTFS file system. It leverages Sysmon Event ID 15 and regex to identify files with a Portable Executable (PE) structure. This activity is significant as it may indicate a threat actor staging malicious code in hidden areas for persistence or future execution. If confirmed malicious, this could allow attackers to execute hidden code, maintain persistence, or escalate privileges within the environment.
Suspicious Reg exe Process: endpointEndpointrisk_score:352024-09-30version:7
The following analytic identifies instances of reg.exe being launched from a command prompt (cmd.exe) that was not initiated by the user, as indicated by a parent process other than explorer.exe. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and parent process names. This activity is significant because reg.exe is often used in registry manipulation, which can be indicative of malicious behavior such as persistence mechanisms or system configuration changes. If confirmed malicious, this could allow an attacker to modify critical system settings, potentially leading to privilege escalation or persistent access.
Windows Impair Defenses Disable HVCI: endpointEndpointrisk_score:702024-09-30version:3
The following analytic detects the disabling of Hypervisor-protected Code Integrity (HVCI) by monitoring changes in the Windows registry. It leverages data from the Endpoint datamodel, specifically focusing on registry paths and values related to HVCI settings. This activity is significant because HVCI helps protect the kernel and system processes from tampering by malicious code. If confirmed malicious, disabling HVCI could allow attackers to execute unsigned kernel-mode code, potentially leading to kernel-level rootkits or other severe security breaches.
Windows Impair Defense Disable Defender Protocol Recognition: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable the Windows Defender protocol recognition feature. It leverages data from the Endpoint.Registry data model, specifically looking for changes to the "DisableProtocolRecognition" setting. This activity is significant because disabling protocol recognition can hinder Windows Defender's ability to detect and respond to malware or suspicious software. If confirmed malicious, this action could allow an attacker to bypass antivirus defenses, facilitating further malicious activities such as data exfiltration or system compromise.
Windows Modify Show Compress Color And Info Tip Registry: endpointEndpointrisk_score:252024-12-08version:7
The following analytic detects suspicious modifications to the Windows registry keys related to file compression color and information tips. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the "ShowCompColor" and "ShowInfoTip" values under the "Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced" path. This activity is significant as it was observed in the Hermetic Wiper malware, indicating potential malicious intent to alter file attributes and user interface elements. If confirmed malicious, this could signify an attempt to manipulate file visibility and deceive users, potentially aiding in further malicious activities.
Disabling Remote User Account Control: endpointEndpointrisk_score:422024-12-03version:7
The following analytic identifies modifications to the registry key that controls the enforcement of Windows User Account Control (UAC). It detects changes to the registry path `HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA` where the value is set to `0x00000000`. This activity is significant because disabling UAC can allow unauthorized changes to the system without user consent, potentially leading to privilege escalation. If confirmed malicious, an attacker could gain elevated privileges, making it easier to execute further attacks or maintain persistence within the environment.
Windows Excessive Disabled Services Event: endpointEndpointrisk_score:812024-11-28version:6
The following analytic identifies an excessive number of system events where services are modified from start to disabled. It leverages Windows Event Logs (EventCode 7040) to detect multiple service state changes on a single host. This activity is significant as it may indicate an adversary attempting to disable security applications or other critical services, potentially leading to defense evasion or destructive actions. If confirmed malicious, this behavior could allow attackers to disable security defenses, disrupt system operations, and achieve their objectives on the compromised system.
Windows Impair Defense Configure App Install Control: endpointEndpointrisk_score:492024-11-14version:4
The following analytic detects modifications to the Windows registry that disable the Windows Defender SmartScreen App Install Control feature. It leverages data from the Endpoint.Registry data model to identify changes to specific registry values. This activity is significant because disabling App Install Control can allow users to install potentially malicious web-based applications without restrictions, increasing the risk of security vulnerabilities. If confirmed malicious, this action could lead to the installation of harmful applications, potentially compromising the system and exposing sensitive information.
Windows Disable Lock Workstation Feature Through Registry: endpointEndpointrisk_score:492024-12-08version:7
The following analytic detects a suspicious registry modification that disables the Lock Computer feature in Windows. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableLockWorkstation" with a value of "0x00000001". This activity is significant because it prevents users from locking their screens, a tactic often used by malware, including ransomware, to maintain control over compromised systems. If confirmed malicious, this could allow attackers to sustain their presence and execute further malicious actions without user interruption.
Remote Registry Key modifications: endpointEndpointrisk_score:252024-10-17version:5
This search monitors for remote modifications to registry keys.
Windows Hide Notification Features Through Registry: endpointEndpointrisk_score:492024-12-08version:7
The following analytic detects suspicious registry modifications aimed at hiding common Windows notification features on a compromised host. It leverages data from the Endpoint.Registry data model, focusing on specific registry paths and values. This activity is significant as it is often used by ransomware to obscure visual indicators, increasing the impact of the attack. If confirmed malicious, this could prevent users from noticing critical system alerts, thereby aiding the attacker in maintaining persistence and furthering their malicious activities undetected.
Windows Impair Defense Set Win Defender Smart Screen Level To Warn: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that set the Windows Defender SmartScreen level to "warn." This detection leverages data from the Endpoint.Registry data model, specifically monitoring changes to the ShellSmartScreenLevel registry value. This activity is significant because altering SmartScreen settings to "warn" can reduce immediate suspicion from users, allowing potentially malicious executables to run with just a warning prompt. If confirmed malicious, this could enable attackers to execute harmful files, increasing the risk of successful malware deployment and subsequent system compromise.
Disable Registry Tool: endpointEndpointrisk_score:402024-12-08version:9
The following analytic detects modifications to the Windows registry aimed at disabling the Registry Editor (regedit). It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableRegistryTools" with a value of "0x00000001". This activity is significant because malware, such as RATs or trojans, often disable registry tools to prevent the removal of their entries, aiding in persistence and defense evasion. If confirmed malicious, this could hinder incident response efforts and allow the attacker to maintain control over the compromised system.
Windows Command and Scripting Interpreter Hunting Path Traversal: endpointEndpointrisk_score:362024-10-17version:3
The following analytic identifies path traversal command-line executions, leveraging data from Endpoint Detection and Response (EDR) agents. It detects patterns in command-line arguments indicative of path traversal techniques, such as multiple instances of "/..", "\..", or "\\..". This activity is significant as it often indicates attempts to evade defenses by executing malicious code, such as through msdt.exe. If confirmed malicious, this behavior could allow attackers to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.
Sdclt UAC Bypass: endpointEndpointrisk_score:632024-09-30version:5
The following analytic detects suspicious modifications to the sdclt.exe registry, a technique often used to bypass User Account Control (UAC). It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific registry paths and values associated with sdclt.exe. This activity is significant because UAC bypasses can allow attackers to execute payloads with elevated privileges without user consent. If confirmed malicious, this could lead to unauthorized code execution, privilege escalation, and potential persistence within the environment, posing a severe security risk.
Disabling Task Manager: endpointEndpointrisk_score:422024-12-08version:9
The following analytic identifies modifications to the Windows registry that disable Task Manager. It leverages data from the Endpoint.Registry data model, specifically looking for changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System\\DisableTaskMgr" with a value of "0x00000001". This activity is significant as it is commonly associated with malware such as RATs, Trojans, and worms, which disable Task Manager to prevent users from terminating malicious processes. If confirmed malicious, this could allow attackers to maintain persistence and control over the infected system.
Windows Impair Defenses Disable Auto Logger Session: endpointEndpointrisk_score:812024-12-06version:1
The following analytic detects the disabling of an AutoLogger session or one of its providers, by identifying changes to the Registry values "Start" and "Enabled" part of the "\WMI\Autologger\" key path. It leverages data from the Endpoint.Registry datamodel to monitor specific registry paths and values. This activity is significant as attackers and adversaries can leverage this in order to evade defense and blind EDRs and log ingest tooling. If confirmed malicious, this action could allow an attacker to conceal their activities, making it harder to detect further malicious actions and maintain persistence on the compromised endpoint.
Windows Known Abused DLL Loaded Suspiciously: endpointEndpointrisk_score:102024-09-30version:3
The following analytic detects when DLLs with known abuse history are loaded from an unusual location. This activity may represent an attacker performing a DLL search order or sideload hijacking technique. These techniques are used to gain persistence as well as elevate privileges on the target system. This detection relies on Sysmon EID7 and is compatible with all Officla Sysmon TA versions.
Disabling NoRun Windows App: endpointEndpointrisk_score:252024-12-08version:9
The following analytic detects the modification of the Windows registry to disable the Run application in the Start menu. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "*\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\NoRun" with a value of "0x00000001". This activity is significant because the Run application is a useful shortcut for executing known applications and scripts. If confirmed malicious, this action could hinder system cleaning efforts and make it more difficult to run essential tools, thereby aiding malware persistence.
Windows Impair Defense Disable Web Evaluation: endpointEndpointrisk_score:492024-11-14version:4
The following analytic detects modifications to the Windows registry entry "EnableWebContentEvaluation" to disable Windows Defender web content evaluation. It leverages data from the Endpoint.Registry datamodel, specifically monitoring changes where the registry value is set to "0x00000000". This activity is significant as it indicates an attempt to impair browser security features, potentially allowing malicious web content to bypass security checks. If confirmed malicious, this could lead to users interacting with harmful scripts or unsafe web elements, increasing the risk of system exploitation and security breaches.
Windows Process With NamedPipe CommandLine: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects processes with command lines containing named pipes. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process command-line executions. This behavior is significant as it is often used by adversaries, such as those behind the Olympic Destroyer malware, for inter-process communication post-injection, aiding in defense evasion and privilege escalation. If confirmed malicious, this activity could allow attackers to maintain persistence, escalate privileges, or evade defenses, potentially leading to further compromise of the system.
Windows Common Abused Cmd Shell Risk Behavior: endpointEndpointrisk_score:492024-09-30version:3
The following analytic identifies instances where four or more distinct detection analytics are associated with malicious command line behavior on a specific host. This detection leverages the Command Line Interface (CLI) data from various sources to identify suspicious activities. This behavior is significant as it often indicates attempts to execute malicious commands, access sensitive data, install backdoors, or perform other nefarious actions. If confirmed malicious, attackers could gain unauthorized control, exfiltrate information, escalate privileges, or launch further attacks within the network, leading to severe compromise.
CSC Net On The Fly Compilation: endpointEndpointrisk_score:252024-10-17version:3
The following analytic detects the use of the .NET compiler csc.exe for on-the-fly compilation of potentially malicious .NET code. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on specific command-line patterns associated with csc.exe. This activity is significant because adversaries and malware often use this technique to evade detection by compiling malicious code at runtime. If confirmed malicious, this could allow attackers to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.
Windows Known Abused DLL Created: endpointEndpointrisk_score:102024-09-30version:3
The following analytic identifies the creation of Dynamic Link Libraries (DLLs) with a known history of exploitation in atypical locations. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and filesystem events. This activity is significant as it may indicate DLL search order hijacking or sideloading, techniques used by attackers to execute arbitrary code, maintain persistence, or escalate privileges. If confirmed malicious, this activity could allow attackers to blend in with legitimate operations, posing a severe threat to system integrity and security.
Windows DLL Search Order Hijacking with iscsicpl: endpointEndpointrisk_score:642024-11-28version:5
The following analytic detects DLL search order hijacking involving iscsicpl.exe. It identifies when iscsicpl.exe loads a malicious DLL from a new path, triggering the payload execution. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on child processes spawned by iscsicpl.exe. This activity is significant as it indicates a potential attempt to execute unauthorized code via DLL hijacking. If confirmed malicious, this could allow an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the environment.
Disabling SystemRestore In Registry: endpointEndpointrisk_score:492024-12-08version:9
The following analytic detects the modification of registry keys to disable System Restore on a machine. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with System Restore settings. This activity is significant because disabling System Restore can hinder recovery efforts and is a tactic often used by Remote Access Trojans (RATs) to maintain persistence on an infected system. If confirmed malicious, this action could prevent system recovery, allowing the attacker to sustain their foothold and potentially cause further damage or data loss.
Windows Impair Defense Change Win Defender Throttle Rate: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the ThrottleDetectionEventsRate registry setting in Windows Defender. It leverages data from the Endpoint.Registry datamodel to identify changes in the registry path related to Windows Defender's event logging rate. This activity is significant because altering the ThrottleDetectionEventsRate can reduce the frequency of logged detection events, potentially masking malicious activities. If confirmed malicious, this could allow an attacker to evade detection by decreasing the visibility of security events, thereby hindering incident response and forensic investigations.
Windows Impair Defense Disable PUA Protection: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects a modification in the Windows registry to disable Windows Defender PUA protection by setting PUAProtection to 0. This detection leverages data from the Endpoint.Registry datamodel, focusing on registry path changes related to Windows Defender. Disabling PUA protection is significant as it reduces defenses against Potentially Unwanted Applications (PUAs), which, while not always malicious, can negatively impact user experience and security. If confirmed malicious, this activity could allow an attacker to introduce adware, browser toolbars, or other unwanted software, potentially compromising system integrity and user productivity.
Windows LOLBAS Executed As Renamed File: endpointEndpointrisk_score:402024-09-30version:2
The following analytic identifies a LOLBAS process being executed where it's process name does not match it's original file name attribute. Processes that have been renamed and executed may be an indicator that an adversary is attempting to evade defenses or execute malicious code. The LOLBAS project documents Windows native binaries that can be abused by threat actors to perform tasks like executing malicious code.
Windows Impair Defense Disable Win Defender Compute File Hashes: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable Windows Defender's file hash computation by setting the EnableFileHashComputation value to 0. This detection leverages data from the Endpoint.Registry data model, focusing on changes to the specific registry path associated with Windows Defender. Disabling file hash computation can significantly impair Windows Defender's ability to detect and scan for malware, making it a critical behavior to monitor. If confirmed malicious, this activity could allow attackers to bypass Windows Defender, facilitating undetected malware execution and persistence in the environment.
Windows Impair Defense Change Win Defender Tracing Level: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry specifically targeting the "WppTracingLevel" setting within Windows Defender. This detection leverages data from the Endpoint.Registry data model to identify changes in the registry path associated with Windows Defender tracing levels. Such modifications are significant as they can impair the diagnostic capabilities of Windows Defender, potentially hiding malicious activities. If confirmed malicious, this activity could allow an attacker to evade detection and maintain persistence within the environment, leading to further compromise and data exfiltration.
Disabling CMD Application: endpointEndpointrisk_score:252024-12-08version:9
The following analytic detects modifications to the registry that disable the CMD prompt application. It leverages data from the Endpoint.Registry data model, specifically looking for changes to the "DisableCMD" registry value. This activity is significant because disabling CMD can hinder an analyst's ability to investigate and remediate threats, a tactic often used by malware such as RATs, Trojans, or Worms. If confirmed malicious, this could prevent security teams from using CMD for directory and file traversal, complicating incident response and allowing the attacker to maintain persistence.
Windows Impair Defense Disable Realtime Signature Delivery: endpointEndpointrisk_score:492024-09-30version:3
The following analytic detects modifications to the Windows registry that disable the Windows Defender real-time signature delivery feature. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path associated with Windows Defender signature updates. This activity is significant because disabling real-time signature delivery can prevent Windows Defender from receiving timely malware definitions, reducing its effectiveness. If confirmed malicious, this action could allow attackers to bypass malware detection, leading to potential system compromise and persistent threats.