Potential Credential Dumping of LSASS (Windows Event Log)

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

This use case looks for access requests to lsass by a user, which may indicate an attempt to dump credentials

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1003` OS Credential Dumping

Telemetry coverage

Provider	Record / event type
Security-Auditing	Event ID 4656: A handle to an object was requested.
Security-Auditing	Event ID 4663: An attempt was made to access an object.

Rule body

id: '19351.33713'
title: Potential Credential Dumping of LSASS
description: 'This use case looks for access requests to lsass by a user, which may
  indicate an attempt to dump credentials. -- Threat Actor Association: Alloy Taurus/Gallium'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` ((TERM(EventCode=4656) OR
  "<EventID>4656<") ("0x1010" OR "0x40" OR "0x1400" OR "0x100000" OR "0x1410" OR "0x1438"
  OR "0x143a" OR "0x1418" OR "0x1f0fff" OR "0x1f1fff" OR "0x1f2fff" OR "0x1f3fff")
  ) OR ((TERM(EventCode=4663) OR "<EventID>4663<") ("%%4484" OR "%%4416") ) "lsass.exe"
  | regex user!=".*\$" | table _time, host, user process, process_*, signature_id,
  parent_* | bin span=5s | stats values(*) as * by _time, host | where match(signature_id,
  "4656") and match(signature_id, "4663") '
techniques:
- credential-access:os credential dumping
technique_id: 
- T1003
data_category:
- Windows event logs
references: null

Stages and Predicates

Stage 1: `search`

`get_endpoint_data` `get_endpoint_data_winevent` ((TERM(EventCode=4656) OR "<EventID>4656<") ("0x1010" OR "0x40" OR "0x1400" OR "0x100000" OR "0x1410" OR "0x1438" OR "0x143a" OR "0x1418" OR "0x1f0fff" OR "0x1f1fff" OR "0x1f2fff" OR "0x1f3fff") ) OR ((TERM(EventCode=4663) OR "<EventID>4663<") ("%%4484" OR "%%4416") ) "lsass.exe"

Stage 2: `regex`

| regex user!=".*\$"

Stage 3: `table`

| table _time, host, user process, process_*, signature_id, parent_*

Stage 4: `bucket`

| bin span=5s

Stage 5: `stats`

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

Stage 6: `where`

| where match(signature_id, "4656") and match(signature_id, "4663")

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`user`	regex_match	`".*$"`	`excludes:user`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`EventCode`	eq	`4656` corpus 19 (splunk 15, kusto 4) `4663` corpus 35 (splunk 30, kusto 5)	`field:"EventID" kind:eq`
`signature_id`	regex_match	`"4656"` corpus 3 (splunk 3) `"4663"` corpus 2 (splunk 2)	`field:"signature_id" kind:regex_match`

Search terms

These SPL tokens match against raw event text.

Stage	Term
1	`"<EventID>4656<"`
1	`"0x1010"`
1	`"0x40"`
1	`"0x1400"`
1	`"0x100000"`
1	`"0x1410"`
1	`"0x1438"`
1	`"0x143a"`
1	`"0x1418"`
1	`"0x1f0fff"`
1	`"0x1f1fff"`
1	`"0x1f2fff"`
1	`"0x1f3fff"`
1	`"<EventID>4663<"`
1	`"%%4484"`
1	`"%%4416"`
1	`"lsass.exe"`