Detection rules › Splunk

Detect Computer Changed with Anonymous Account

Author
Rod Soto, Jose Hernandez, Splunk
Source
upstream

The following analytic detects changes to computer accounts using an anonymous logon. It leverages Windows Security Event Codes 4742 (Computer Change) with a SubjectUserName of a value "ANONYMOUS LOGON". This activity can be significant because anonymous logons should not typically be modifying computer accounts, indicating potential unauthorized access or misconfiguration. If confirmed malicious, this could allow an attacker to alter computer accounts, potentially leading to privilege escalation or persistent access within the network.

MITRE ATT&CK coverage

TacticTechniques
Lateral MovementT1210 Exploitation of Remote Services

Event coverage

ProviderEvent IDTitle
Security-Auditing4742A computer account was changed.

Stages and Predicates

Stage 1: search

search EventCode=4742 PasswordLastSet="*" SubjectUserName="ANONYMOUS LOGON"

Stage 2: stats

stats BY action, app, dest, ProcessID, PasswordLastSet, signature, signature_id, src_user, status, SubjectDomainName, user, user_group, vendor_product

Stage 3: search

search

Stage 4: search

search

Stage 5: 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
EventCodeeq
  • 4742 corpus 4 (splunk 4)
PasswordLastSeteq
  • "*"
SubjectUserNameeq
  • "ANONYMOUS LOGON" corpus 2 (splunk 2)