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Detection rules › Splunk

SecretsDump Credential Harvest (Windows Event Log)

Group by
_time, host, session_id
Source
github.com/anvilogic-forge/armory

SecretsDump.py Performs various techniques to dump hashes from the remote machine without executing any agent there

MITRE ATT&CK coverage

TacticTechniques
Credential Access

References

Telemetry coverage

ProviderRecord / event type
Security-AuditingEvent ID 4624: An account was successfully logged on.
Security-AuditingEvent ID 4661: A handle to an object was requested.
Security-AuditingEvent ID 5145: A network share object was checked to see whether client can be granted desired access.

Rule body

id: '5412.5535'
title: SecretsDump Credential Harvest
description: 'SecretsDump.py Performs various techniques to dump hashes from the remote
  machine without executing any agent there. -- Threat Actor Association: APT15, Scattered
  Spider (aka. 0ktapus, UNC3944), Volt Typhoon -- Software Association: Rhysida'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` ((TERM(EventCode=4624) OR
  "<EventID>4624<") Authentication_Package="NTLM") OR ((TERM(EventCode=4661) OR "<EventID>4661<")
  TERM(SAM)) OR ((TERM(EventCode=5145) OR "<EventID>5145<") TERM(SAMR)) | rex field=_raw
  "Account Name:\s+(?<user>\S+\$)" | table _time, host, user signature_id, Account_Name,
  user, Relative_Target_Name, signature_id, src_ip, session_id | bin span=1s | stats
  values(*) as * by _time, host, session_id | where (match(signature_id, "(?i)4624")
  AND match(signature_id, "(?i)5145") AND match(signature_id, "(?i)4661")) | eventstats
  dc(src_ip) as dc_src_ip by host| where dc_src_ip=1 '
techniques:
- credential-access:os credential dumping:security account manager
technique_id:
- T1003.002
data_category:
- Windows event logs
references:
- https://github.com/SecureAuthCorp/impacket/blob/master/examples/secretsdump.py

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` ((TERM(EventCode=4624) OR "<EventID>4624<") Authentication_Package="NTLM") OR ((TERM(EventCode=4661) OR "<EventID>4661<") TERM(SAM)) OR ((TERM(EventCode=5145) OR "<EventID>5145<") TERM(SAMR))

Stage 2: rex

| rex field=_raw "Account Name:\s+(?<user>\S+\$)"

Stage 3: table

| table _time, host, user signature_id, Account_Name, user, Relative_Target_Name, signature_id, src_ip, session_id

Stage 4: bucket

| bin span=1s

Stage 5: stats

| stats values(*) as * by _time, host, session_id

Stage 6: where

| where (match(signature_id, "(?i)4624") AND match(signature_id, "(?i)5145") AND match(signature_id, "(?i)4661"))

Stage 7: eventstats

| eventstats dc(src_ip) as dc_src_ip by host

Stage 8: where

| where dc_src_ip=1

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Authentication_Packageeq
  • "NTLM" corpus 3 (splunk 3)
field:"Authentication_Package" kind:eq
EventCodeeq
  • 4624 corpus 29 (splunk 13, kusto 11, chronicle 4, elastic 1)
  • 4661
  • 5145 corpus 23 (splunk 16, elastic 5, kusto 2)
field:"EventID" kind:eq
dc_src_ipeq
  • 1
field:"dc_src_ip" kind:eq value:"1"
signature_idregex_match
  • "(?i)4624" corpus 2 (splunk 2)
  • "(?i)4661"
  • "(?i)5145" corpus 2 (splunk 2)
field:"signature_id" kind:regex_match

Search terms

These SPL tokens match against raw event text.

StageTerm
1"<EventID>4624<"
1"<EventID>4661<"
1SAM
1"<EventID>5145<"
1SAMR