Detection rules › Splunk

Windows AD Short Lived Domain Controller SPN Attribute

Author
Dean Luxton
Source
upstream

The following analytic detects the temporary addition of a global catalog SPN or a DRS RPC SPN to an Active Directory computer object, indicative of a potential DCShadow attack. This detection leverages EventCode 5136 from the wineventlog_security data source, focusing on specific SPN attribute changes. This activity is significant as DCShadow attacks allow attackers with privileged access to register rogue Domain Controllers, enabling unauthorized changes to the AD infrastructure. If confirmed malicious, this could lead to unauthorized replication of changes, including credentials and keys, compromising the entire domain's security.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1207 Rogue Domain Controller

Event coverage

ProviderEvent IDTitle
Security-Auditing4624An account was successfully logged on.
Security-Auditing5136A directory service object was modified.

Stages and Predicates

Stage 1: search

search (AttributeValue="E3514235-4B06-11D1-AB04-00C04FC2DCD2/*" OR AttributeValue="GC/*") AttributeLDAPDisplayName="servicePrincipalName" EventCode=5136

Stage 2: stats

stats BY Logon_ID

Stage 3: eval

eval ... using (duration)

Stage 4: where

where short_lived="TRUE"

Stage 5: replace

replace

Stage 6: rename

rename

Stage 7: appendpipe

appendpipe

Stage 8: search

search `macro`

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
AttributeLDAPDisplayNameeq
  • servicePrincipalName corpus 6 (splunk 3, sigma 2, elastic 1)
AttributeValueeq
  • "E3514235-4B06-11D1-AB04-00C04FC2DCD2/*"
  • "GC/*"
EventCodeeq
  • 5136 corpus 22 (splunk 22)
short_livedeq
  • "TRUE"