Detection rules › Sigma

Portable Gpg.EXE Execution

Severity
medium
Author
frack113, Nasreddine Bencherchali (Nextron Systems)
Source
upstream

Detects the execution of "gpg.exe" from uncommon location. Often used by ransomware and loaders to decrypt/encrypt data.

MITRE ATT&CK coverage

TacticTechniques
ImpactT1486 Data Encrypted for Impact

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation

Stages and Predicates

Stage 1: selection

or:
Description: 'GnuPG’s OpenPGP tool'
Image|endswith: '\gpg.exe'
Image|endswith: '\gpg2.exe'
OriginalFileName: gpg.exe

Stage 2: not 1 of filter_main_legit_location

or:
Image|contains: ':\Program Files (x86)\GNU\GnuPG\bin\'
Image|contains: ':\Program Files (x86)\GnuPG VS-Desktop\'
Image|contains: ':\Program Files (x86)\GnuPG\bin\'
Image|contains: ':\Program Files (x86)\Gpg4win\bin\'

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
Descriptioneq
  • GnuPG’s OpenPGP tool corpus 4 (sigma 4)
Imageends_with
  • \gpg.exe corpus 5 (sigma 5)
  • \gpg2.exe corpus 5 (sigma 5)
Imagematch
  • :\Program Files (x86)\GNU\GnuPG\bin\
  • :\Program Files (x86)\GnuPG VS-Desktop\
  • :\Program Files (x86)\GnuPG\bin\
  • :\Program Files (x86)\Gpg4win\bin\
OriginalFileNameeq
  • gpg.exe corpus 2 (sigma 2)