Detection rules › Splunk
LocalAccountTokenFilterPolicy Registry Value Modified (Sysmon)
The HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\LocalAccountTokenFilterPolicy key is responsible for controlling how local accounts are filtered when they are used to access a Windows system remotely. By setting the key to value '1', it effectively disables Remote UAC filtering for local accounts, allowing local admin accounts to use elevated tokens (with full admin rights when connecting remotely). This may leave a system vulnerable to Pass the Hash attacks. This use case detects registry modification events or process executions with registry modification commands targeting LocalAccountTokenFilterPolicy.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1112 Modify Registry |
| Defense Impairment | T1112 Modify Registry |
| Lateral Movement | T1550.002 Use Alternate Authentication Material: Pass the Hash |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Sysmon | Event ID 12 | RegistryEvent (Object create and delete) |
| Sysmon | Event ID 13 | RegistryEvent (Value Set) |
Rule body yaml
id: '40510.73996'
title: LocalAccountTokenFilterPolicy Registry Value Modified
description: The HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\LocalAccountTokenFilterPolicy
key is responsible for controlling how local accounts are filtered when they are
used to access a Windows system remotely. By setting the key to value '1', it effectively
disables Remote UAC filtering for local accounts, allowing local admin accounts
to use elevated tokens (with full admin rights when connecting remotely). This may
leave a system vulnerable to Pass the Hash attacks. This use case detects registry
modification events or process executions with registry modification commands targeting
LocalAccountTokenFilterPolicy.
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (((TERM(EventCode=1) OR "<EventID>1<")
"Set-ItemProperty" OR "sp " OR "ADD") OR (TERM(EventCode=12) OR "<EventID>12<")
OR TERM(EventCode=13) OR "<EventID>13<") "\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System"
"LocalAccountTokenFilterPolicy" | table _time, host, user user, process, process_*,
parent_* | bin span=1s | stats values(*) as * by _time, host '
techniques:
- defense-evasion:modify registry
- defense-evasion:use alternate authentication material:pass the hash
technique_id:
- T1112
- T1550.002
data_category:
- Windows Sysmon
references:
- https://www.security.com/threat-intelligence/china-southeast-asia-espionage
- https://posts.specterops.io/pass-the-hash-is-dead-long-live-localaccounttokenfilterpolicy-506c25a7c167
- https://kb.cybertecsecurity.com/knowledge/localaccounttokenfilterpolicy
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` (((TERM(EventCode=1) OR "<EventID>1<") "Set-ItemProperty" OR "sp " OR "ADD") OR (TERM(EventCode=12) OR "<EventID>12<") OR TERM(EventCode=13) OR "<EventID>13<") "\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System" "LocalAccountTokenFilterPolicy"
Stage 2: table
| table _time, host, user user, process, process_*, parent_*
Stage 3: bucket
| bin span=1s
Stage 4: stats
| stats values(*) as * by _time, host
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 |
|
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>1<" |
| 1 | "Set-ItemProperty" |
| 1 | "sp " |
| 1 | "ADD" |
| 1 | TERM |
| 1 | "<EventID>12<" |
| 1 | TERM |
| 1 | "<EventID>13<" |
| 1 | "\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System" |
| 1 | "LocalAccountTokenFilterPolicy" |