PowerShell Suspicious Discovery Related Windows API Functionsedit
This rule detects the use of discovery-related Windows API functions in PowerShell Scripts. Attackers can use these functions to perform various situational awareness related activities, like enumerating users, shares, sessions, domain trusts, groups, etc.
Rule type: query
Rule indices:
- winlogbeat-*
- logs-windows.*
Severity: medium
Risk score: 47
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Discovery
Version: 4 (version history)
Added (Elastic Stack release): 7.16.0
Last modified (Elastic Stack release): 8.1.0
Rule authors: Elastic
Rule license: Elastic License v2
Potential false positivesedit
Legitimate PowerShell scripts that make use of these functions.
Investigation guideedit
## Triage and analysis. ### Investigating PowerShell Suspicious Discovery Related Windows API Functions PowerShell is one of the main tools used by system administrators for automation, report routines, and other tasks. Attackers can use PowerShell to interact with the Win32 API to bypass file based antivirus detections, using libraries like PSReflect or Get-ProcAddress Cmdlet. #### Possible investigation steps: - Examine script content that triggered the detection. - Investigate script execution chain (parent process tree). - Inspect any file or network events from the suspicious PowerShell host process instance. - If the action is suspicious for the user, check for any other activities done by the user in the last 48 hours. ### False Positive Analysis - Verify whether the script content is malicious/harmful. ### Related Rules - PowerShell PSReflect Script - 56f2e9b5-4803-4e44-a0a4-a52dc79d57fe ### Response and Remediation - Immediate response should be taken to validate, investigate, and potentially contain the activity to prevent further post-compromise behavior. ## Config The 'PowerShell Script Block Logging' logging policy must be enabled. Steps to implement the logging policy with with Advanced Audit Configuration: ``` Computer Configuration > Administrative Templates > Windows PowerShell > Turn on PowerShell Script Block Logging (Enable) ``` Steps to implement the logging policy via registry: ``` reg add "hklm\SOFTWARE\Policies\Microsoft\Windows\PowerShell\ScriptBlockLogging" /v EnableScriptBlockLogging /t REG_DWORD /d 1 ```
Rule queryedit
event.category:process and powershell.file.script_block_text : ( NetShareEnum or NetWkstaUserEnum or NetSessionEnum or NetLocalGroupEnum or NetLocalGroupGetMembers or DsGetSiteName or DsEnumerateDomainTrusts or WTSEnumerateSessionsEx or WTSQuerySessionInformation or LsaGetLogonSessionData or QueryServiceObjectSecurity )
Threat mappingedit
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Discovery
- ID: TA0007
- Reference URL: https://attack.mitre.org/tactics/TA0007/
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Technique:
- Name: Network Share Discovery
- ID: T1135
- Reference URL: https://attack.mitre.org/techniques/T1135/
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Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
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Technique:
- Name: Command and Scripting Interpreter
- ID: T1059
- Reference URL: https://attack.mitre.org/techniques/T1059/
Rule version historyedit
- Version 4 (8.1.0 release)
-
- Formatting only
- Version 3 (8.0.0 release)
-
-
Updated query, changed from:
event.code:"4104" and powershell.file.script_block_text : ( NetShareEnum or NetWkstaUserEnum or NetSessionEnum or NetLocalGroupEnum or NetLocalGroupGetMembers or DsGetSiteName or DsEnumerateDomainTrusts or WTSEnumerateSessionsEx or WTSQuerySessionInformation or LsaGetLogonSessionData or QueryServiceObjectSecurity )
-