Detection rules › Sigma

Account set with Kerberos DES encryption activated (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 DES Kerberos encryption to perform ticket brutforce.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1098 Account Manipulation

Event coverage

ProviderEventTitle
Security-AuditingEvent ID 4738A user account was changed.

Rule body yaml

title: Account set with Kerberos DES encryption activated (weakness introduction)
description: Detects scenarios where an attacker set an account with DES Kerberos encryption to perform ticket brutforce.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0003-Persistence/T1098.xxx-Account%20manipulation
- https://docs.microsoft.com/en-us/services-hub/health/remediation-steps-ad/remove-the-highly-insecure-des-encryption-from-user-accounts
tags:
- attack.persistence
- attack.t1098
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 4738
    UserAccountControl: '%%2095' # Use only Kerberos DES encryption types - TRUE
  condition: selection
falsepositives:
- None
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  EventID: 4738
  UserAccountControl: '%%2095'

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
UserAccountControleq
  • %%2095