Detection rules › Sigma

File Encryption Using Gpg4win

Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Source
upstream

Detects usage of Gpg4win to encrypt files

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation

Stages and Predicates

Stage 1: all of selection_metadata

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

Stage 2: all of selection_cli

CommandLine|contains: ' -c '
CommandLine|contains: passphrase

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
CommandLinematch
  • -c corpus 11 (sigma 11)
  • passphrase corpus 2 (sigma 2)
Descriptioneq
  • GnuPG’s OpenPGP tool corpus 4 (sigma 4)
Imageends_with
  • \gpg.exe corpus 5 (sigma 5)
  • \gpg2.exe corpus 5 (sigma 5)