Sigma rule: AgentExecutor PowerShell Execution

Rule

Title

AgentExecutor PowerShell Execution

Status

test

Level

medium

Author

Nasreddine Bencherchali (Nextron Systems), memory-shards

Date

2022-12-24

Modified

2024-08-07

File

rules/windows/process_creation/proc_creation_win_agentexecutor_potential_abuse.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects execution of the AgentExecutor.exe binary. Which can be abused as a LOLBIN to execute powershell scripts with the ExecutionPolicy "Bypass" or any binary named "powershell.exe" located in the path provided by 6th positional argument

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image: '\AgentExecutor.exe'
    - OriginalFileName: 'AgentExecutor.exe'
selection_cli:
    # Example:
    #   AgentExecutor.exe -powershell [scriptPath] [outputFilePath] [errorFilePath] [timeoutFilePath] [timeoutSeconds] [powershellPath] [enforceSignatureCheck] [runAs32BitOn64]
    # Note:
    #   - If [timeoutSeconds] is NULL then it defaults to 60000
    #   - If [enforceSignatureCheck] is:
    #       - "NULL" or "1" then a PowerShell instance is spawned with the args: "-NoProfile -executionPolicy allsigned -file "
    #       - Else a PowerShell instance is spawned with the args: "-NoProfile -executionPolicy bypass -file "
    #   - [powershellPath] is always concatendated to "powershell.exe"
    CommandLine|contains:
        - ' -powershell' # Also covers the "-powershellDetection" flag
        - ' -remediationScript'
filter_main_intune:
    ParentImage|endswith: '\Microsoft.Management.Services.IntuneWindowsAgent.exe'
condition: all of selection_* and not 1 of filter_main_*

False positives (as the rule lists them)

• Legitimate use via Intune management. You exclude script paths and names to reduce FP rate

Tags

• attack.stealth
• attack.t1218

MITRE ATT&CK ids this rule names

• T1218

Related rules

• c0b40568-b1e9-4b03-8d6c-b096da6da9ab (similar)

References

• https://twitter.com/lefterispan/status/1286259016436514816
• https://lolbas-project.github.io/lolbas/OtherMSBinaries/Agentexecutor/
• https://learn.microsoft.com/en-us/mem/intune/apps/intune-management-extension
• https://twitter.com/jseerden/status/1247985304667066373/photo/1

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_agentexecutor_potential_abuse.yml