Detection rules › Sigma

Removal Of AMSI Provider Registry Keys

Severity
high
Author
frack113
Source
upstream

Detects the deletion of AMSI provider registry key entries in HKLM\Software\Microsoft\AMSI. This technique could be used by an attacker in order to disable AMSI inspection.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1562.001 Impair Defenses: Disable or Modify Tools

Event coverage

ProviderEvent IDTitle
Sysmon14RegistryEvent (Key and Value Rename)

Stages and Predicates

Stage 1: selection

or:
TargetObject|endswith: '{2781761E-28E0-4109-99FE-B9D127C57AFE}'
TargetObject|endswith: '{A7C452EF-8E9F-42EB-9F2B-245613CA0DC9}'

Stage 2: not 1 of filter_main_defender

or:
Image|startswith: 'C:\Program Files (x86)\Windows Defender\'
Image|startswith: 'C:\Program Files\Windows Defender\'
Image|startswith: 'C:\ProgramData\Microsoft\Windows Defender\Platform\'
Image|endswith: '\MsMpEng.exe'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \MsMpEng.exe corpus 13 (sigma 13)
Imagestarts_with
  • C:\Program Files (x86)\Windows Defender\ corpus 5 (sigma 5)
  • C:\Program Files\Windows Defender\ corpus 5 (sigma 5)
  • C:\ProgramData\Microsoft\Windows Defender\Platform\ corpus 7 (sigma 7)
TargetObjectends_with
  • {2781761E-28E0-4109-99FE-B9D127C57AFE}
  • {A7C452EF-8E9F-42EB-9F2B-245613CA0DC9}