Name:Windows DotNet Binary in Non Standard Path id:fddf3b56-7933-11ec-98a6-acde48001122 version:14 date:None author:Michael Haag, Splunk status:production type:TTP Description:The following analytic detects the execution of native .NET binaries from non-standard directories within the Windows operating system.
It leverages Endpoint Detection and Response (EDR) telemetry, comparing process names and original file names against a predefined lookup "is_net_windows_file".
This activity is significant because adversaries may move .NET binaries to unconventional paths to evade detection and execute malicious code.
If confirmed malicious, this behavior could allow attackers to execute arbitrary code, escalate privileges, or maintain persistence within the environment, posing a significant security risk.
Also this analytic leverages a sub-search to enhance performance. sub-searches have limitations on the amount of data they can return. Keep this in mind if you have an extensive list of ransomware note file names.
Data_source:
-Sysmon EventID 1
-Windows Event Log Security 4688
-CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes where NOT Processes.process_path IN ( "*:\\Windows\\ADWS\\*", "*:\\Windows\\Microsoft.NET\\*", "*:\\Windows\\NetworkController\\*", "*:\\Windows\\System32\\*", "*:\\Windows\\SystemApps\\*", "*:\\Windows\\SysWOW64\\*", "*:\\Windows\\WinSxS\\*" ) ( [ | inputlookup is_net_windows_file
| search netFile=true
| fields originalFileName
| rename originalFileName as Processes.original_file_name
how_to_implement:The detection is based on data that originates from Endpoint Detection
and Response (EDR) agents. These agents are designed to provide security-related
telemetry from the endpoints where the agent is installed. To implement this search,
you must ingest logs that contain the process GUID, process name, and parent process.
Additionally, you must ingest complete command-line executions. These logs must
be processed using the appropriate Splunk Technology Add-ons that are specific to
the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
data model. Use the Splunk Common Information Model (CIM) to normalize the field
names and speed up the data modeling process.
known_false_positives:False positives may be present and filtering may be required. Certain utilities will run from non-standard paths based on the third-party application in use. References: -https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1036.003/T1036.003.yaml -https://attack.mitre.org/techniques/T1036/003/ -https://www.microsoft.com/security/blog/2022/01/15/destructive-malware-targeting-ukrainian-organizations/ -https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.004/T1218.004.md drilldown_searches: name:'View the detection results for - "$user$" and "$dest$"' search:'%original_detection_search% | search user = "$user$" dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$user$" and "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'7d' latest_offset:'0' analytic_story:['Masquerading - Rename System Utilities', 'Ransomware', 'Unusual Processes', 'Signed Binary Proxy Execution InstallUtil', 'Data Destruction', 'WhisperGate']
