Detection rules › Splunk

Windows Short Lived DNS Record

Author
Raven Tait, Splunk
Source
upstream

The following analytic identifies the creation and quick deletion of a DNS object within 300 seconds in an Active Directory environment, indicative of a potential attack abusing DNS. This detection leverages Windows Security Event Codes 5136 and 5137, analyzing the duration between these events. This activity is significant as temporary DNS entries allows attackers to cause unexpecting network trafficking, leading to potential compromise.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1187 Forced Authentication, T1557.001 Adversary-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay
CollectionT1557.001 Adversary-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay
Command & ControlT1071.004 Application Layer Protocol: DNS

Event coverage

ProviderEvent IDTitle
Security-Auditing5136A directory service object was modified.
Security-Auditing5137A directory service object was created.

Stages and Predicates

Stage 1: search

search ((AttributeLDAPDisplayName="dNSTombstoned" AttributeValue="TRUE" EventCode=5136 ObjectClass="dnsNode") OR (EventCode=5137 ObjectClass="dnsNode"))

Stage 2: stats

stats BY ObjectGUID

Stage 3: where

where

Stage 4: eval

eval ... using (firstTime, lastTime)

Stage 5: where

where time_diff<=300

Stage 6: table

table ObjectGUID, dest, dns_record, firstTime, lastTime, time_diff, user

Stage 7: search

search

Stage 8: search

search

Stage 9: 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
  • "dNSTombstoned"
AttributeValueeq
  • "TRUE"
EventCodeeq
  • 5136 corpus 22 (splunk 22)
  • 5137 corpus 3 (splunk 3)
ObjectClasseq
  • "dnsNode" corpus 2 (splunk 2)
time_diffle
  • 300

Neighbors

Often fire together

Rules that target events appearing in the same incident timelines. They pattern-match on adjacent steps of the same TTP, so an alert from one is often paired with alerts from these. Useful for triage context and for assembling chained-detection rules.

Share event IDs (chain-detection candidates)

Rules that observe the same Windows event-ID pairs as this one. If you're authoring a multi-stage / sequence rule that spans these events, these are the existing detections that already cover one or both endpoints.