LoFP / creation of legitimate files in sudoers.d folder as part of administrator work

Techniques

• t1548
• t1548.003

Sample rules

Persistence Via Sudoers.d Files

• source: sigma
• technicques:
  • t1548
  • t1548.003

Description

Detects the creation or modification of files within the “sudoers.d” directory on Linux systems. Such activity may indicate an attempt to establish or maintain privilege escalation by granting specific users elevated permissions. Unauthorized changes to sudoers files are a common technique used by attackers to persist administrative access.

Detection logic

condition: selection and not 1 of filter_main_*
filter_main_dpkg:
  Image|endswith: /usr/bin/dpkg
  TargetFilename: /etc/sudoers.d/README.dpkg-new
selection:
  TargetFilename|startswith: /etc/sudoers.d/