Detection rules › Splunk

EnableLUA Registry Value Modified (Sysmon)

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

Adversaries may bypass UAC mechanisms to elevate process privileges on system. Windows User Account Control (UAC) allows a program to elevate its privileges (tracked as integrity levels ranging from low to high) to perform a task under administrator-level permissions, possibly by prompting the user for confirmation. This use case detects registry modification events or process executions with registry modification commands targeting HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA.

MITRE ATT&CK coverage

References

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation
SysmonEvent ID 13RegistryEvent (Value Set)

Rule body yaml

id: '31087.55677'
title: EnableLUA Registry Value Modified
description: Adversaries may bypass UAC mechanisms to elevate process privileges on
  system. Windows User Account Control (UAC) allows a program to elevate its privileges
  (tracked as integrity levels ranging from low to high) to perform a task under administrator-level
  permissions, possibly by prompting the user for confirmation. This use case detects
  registry modification events or process executions with registry modification commands
  targeting HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA.
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=13) OR "<EventID>13<"))
  "EnableLUA" "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System" | table
  _time, host, user, process process_name, parent_process_name, signature_id, dest_ip,
  registry_value_name | bin span=1s | stats values(*) as * by _time, host '
techniques:
- privilege-escalation:abuse elevation control mechanism:bypass user account control
technique_id:
- T1548.002
data_category:
- Windows Sysmon
references:
- https://attack.mitre.org/techniques/T1548/002/

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=13) OR "<EventID>13<")) "EnableLUA" "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System"

Stage 2: table

| table _time, host, user, process process_name, parent_process_name, signature_id, dest_ip, registry_value_name

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.

FieldKindValues
EventCodeeq
  • 1 corpus 237 (splunk 224, kusto 13)
  • 13 corpus 22 (splunk 18, kusto 4)

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.

StageTerm
1TERM
1"<EventID>1<"
1"Set-ItemProperty"
1"sp "
1"ADD"
1TERM
1"<EventID>13<"
1"EnableLUA"
1"SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Policies\\System"