Detection rules › Sigma

Account set with reversible encryption (weakness introduction)

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

Detects scenarios where an attacker set an account with reversible encryption to facilitate brutforce or cracking operations.

Known false positives

  • None

MITRE ATT&CK coverage

TacticTechniques
Persistence

Telemetry coverage

Rule body

title: Account set with reversible encryption (weakness introduction)
description: Detects scenarios where an attacker set an account with reversible encryption to facilitate brutforce or cracking operations.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0003-Persistence/T1098.xxx-Account%20manipulation
- https://www.blackhillsinfosec.com/how-i-cracked-a-128-bit-password/
tags:
- attack.persistence
- attack.t1098
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 4738
    UserAccountControl: '%%2091' # Store password using reversible encryption - True
  condition: selection
falsepositives:
- None
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  EventID: 4738
  UserAccountControl: '%%2091'

Indicators

These rows show field, operator, and value matches.