Detection rules › Sigma

Fortinet APT group abuse on Windows (user)

Status
experimental
Severity
high
Log source
product windows, service security
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where APT actors exploits Fortinet vulnerabilities to gain access into Windows infrastructure.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1136 Create Account

Event coverage

ProviderEventTitle
Security-AuditingEvent ID 4720A user account was created.

Rule body yaml

title: Fortinet APT group abuse on Windows (user)
description: Detects scenarios where APT actors exploits Fortinet vulnerabilities to gain access into Windows infrastructure.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/EVTX_full_APT_attack_steps
- https://www.aha.org/system/files/media/file/2021/05/fbi-flash-tlp-white-apt-actors-exploiting-fortinet-vulnerabilities-to-gain-access-for-malicious-activity-5-27-21.pdf
- https://www.securityweek.com/fbi-shares-iocs-apt-attacks-exploiting-fortinet-vulnerabilities
tags:
- attack.persistence
- attack.t1136
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 4720
    TargetUserName:
      - elie
      - WADGUtilityAccount
  condition: selection
falsepositives:
- None
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  EventID: 4720
  TargetUserName:
    - elie
    - WADGUtilityAccount

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
TargetUserNameeq
  • WADGUtilityAccount
  • elie