Microsoft MSHTML Remote Code Execution CVE-2021-40444

• Office Spawning Control :
  endpoint Endpoint risk_score:80 2024-11-28 version:8
  The following analytic identifies instances where `control.exe` is spawned by a Microsoft Office product. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and parent process relationships. This activity is significant because it can indicate exploitation attempts related to CVE-2021-40444, where `control.exe` is used to execute malicious .cpl or .inf files. If confirmed malicious, this behavior could allow an attacker to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further lateral movement within the network.


• Control Loading from World Writable Directory :
  endpoint Endpoint risk_score:80 2024-11-28 version:5
  The following analytic identifies instances of control.exe loading a .cpl or .inf file from a writable directory, which is related to CVE-2021-40444. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions mapped to the `Processes` node of the `Endpoint` data model. This activity is significant as it may indicate an attempt to exploit a known vulnerability, potentially leading to unauthorized code execution. If confirmed malicious, this could allow an attacker to gain control over the affected system, leading to further compromise.


• Rundll32 Control RunDLL World Writable Directory :
  endpoint Endpoint risk_score:80 2024-11-28 version:5
  The following analytic detects the execution of rundll32.exe with the `Control_RunDLL` command, loading files from world-writable directories such as windows\temp, programdata, or appdata. This detection leverages Endpoint Detection and Response (EDR) telemetry, focusing on process command-line data and specific directory paths. This activity is significant as it may indicate an attempt to exploit CVE-2021-40444 or similar vulnerabilities, allowing attackers to execute arbitrary code. If confirmed malicious, this could lead to unauthorized code execution, privilege escalation, or persistent access within the environment.


• MSHTML Module Load in Office Product :
  endpoint Endpoint risk_score:80 2024-09-30 version:5
  The following analytic detects the loading of the mshtml.dll module into an Office product, which is indicative of CVE-2021-40444 exploitation. It leverages Sysmon EventID 7 to monitor image loads by specific Office processes. This activity is significant because it can indicate an attempt to exploit a vulnerability in the MSHTML component via a malicious document. If confirmed malicious, this could allow an attacker to execute arbitrary code, potentially leading to system compromise, data exfiltration, or further network penetration.


• Rundll32 Control RunDLL Hunt :
  endpoint Endpoint risk_score:15 2024-10-17 version:4
  The following analytic identifies instances of rundll32.exe executing with `Control_RunDLL` in the command line, which is indicative of loading a .cpl or other file types. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs and command-line arguments. This activity is significant as rundll32.exe can be exploited to execute malicious Control Panel Item files, potentially linked to CVE-2021-40444. If confirmed malicious, this could allow attackers to execute arbitrary code, escalate privileges, or maintain persistence within the environment.


• Office Product Writing cab or inf :
  endpoint Endpoint risk_score:80 2024-11-28 version:8
  The following analytic detects Office products writing .cab or .inf files, indicative of CVE-2021-40444 exploitation. It leverages the Endpoint.Processes and Endpoint.Filesystem data models to identify Office applications creating these file types. This activity is significant as it may signal an attempt to load malicious ActiveX controls and download remote payloads, a known attack vector. If confirmed malicious, this could lead to remote code execution, allowing attackers to gain control over the affected system and potentially compromise sensitive data.