Detection rules › Splunk
Potential Credential Dumping of LSASS (Windows Event Log)
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 |
Event coverage
| Provider | Event | Title |
|---|---|---|
| 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 yaml
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
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
user | regex_match | ".*$" |
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.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
signature_id | match |
|
Search terms
Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.
| Stage | Term |
|---|---|
| 1 | 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 | TERM |
| 1 | "<EventID>4663<" |
| 1 | "%%4484" |
| 1 | "%%4416" |
| 1 | "lsass.exe" |