Sigma rule: Potentially Suspicious Execution Of Regasm/Regsvcs From Uncommon Location

Rule

Title

Potentially Suspicious Execution Of Regasm/Regsvcs From Uncommon Location

Status

test

Level

medium

Author

Nasreddine Bencherchali (Nextron Systems)

Date

2022-08-25

Modified

2023-02-13

File

rules/windows/process_creation/proc_creation_win_regasm_regsvcs_uncommon_location_execution.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potentially suspicious execution of the Regasm/Regsvcs utilities from a potentially suspicious location

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith:
          - '\Regsvcs.exe'
          - '\Regasm.exe'
    - OriginalFileName:
          - 'RegSvcs.exe'
          - 'RegAsm.exe'
selection_dir:
    CommandLine|contains:
        # Note: Add more potentially suspicious directories
        - '\AppData\Local\Temp\'
        - '\Microsoft\Windows\Start Menu\Programs\Startup\'
        - '\PerfLogs\'
        - '\Users\Public\'
        - '\Windows\Temp\'
        # - '\Desktop\'
        # - '\Downloads\'
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.stealth
• attack.t1218.009

MITRE ATT&CK ids this rule names

• T1218.009

Related rules

• e9f8f8cc-07cc-4e81-b724-f387db9175e4 (derived)

References

• https://www.fortiguard.com/threat-signal-report/4718?s=09
• https://lolbas-project.github.io/lolbas/Binaries/Regasm/
• https://lolbas-project.github.io/lolbas/Binaries/Regsvcs/

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_regasm_regsvcs_uncommon_location_execution.yml