sigmamediumHunting

Potential Regsvr32 Commandline Flag Anomaly

Detects a potential command line flag anomaly related to "regsvr32" in which the "/i" flag is used without the "/n" which should be uncommon.

MITRE ATT&CK

T1218.010

defense-evasion

Detection Query

selection:
  Image|endswith: \regsvr32.exe
  CommandLine|contains|windash: " -i:"
filter_main_flag:
  CommandLine|contains|windash: " -n "
condition: selection and not 1 of filter_main_*

Author

Florian Roth (Nextron Systems)

Created

2019-07-13

Data Sources

windowsProcess Creation Events

Platforms

windows

References

https://twitter.com/sbousseaden/status/1282441816986484737?s=12

Tags

attack.defense-evasionattack.t1218.010

Raw Content

title: Potential Regsvr32 Commandline Flag Anomaly
id: b236190c-1c61-41e9-84b3-3fe03f6d76b0
status: test
description: Detects a potential command line flag anomaly related to "regsvr32" in which the "/i" flag is used without the "/n" which should be uncommon.
references:
    - https://twitter.com/sbousseaden/status/1282441816986484737?s=12
author: Florian Roth (Nextron Systems)
date: 2019-07-13
modified: 2024-03-13
tags:
    - attack.defense-evasion
    - attack.t1218.010
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\regsvr32.exe'
        CommandLine|contains|windash: ' -i:'
    filter_main_flag:
        CommandLine|contains|windash: ' -n '
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Administrator typo might cause some false positives
level: medium