Detection rules › Splunk

Logon Script Registry Key added (PowerShell)

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

Adversaries may use Windows logon scripts automatically executed at logon initialization to establish persistence.

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

id: '5998.6375'
title: Logon Script Registry Key added
description: 'Adversaries may use Windows logon scripts automatically executed at
  logon initialization to establish persistence. '
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` TERM(EventCode=4104) (TERM(reg)
  OR "reg.exe") TERM(add) TERM(UserInitMprLogonScript) | table _time, host, user process,
  process_*, singature_id | bin span=1s | stats values(*) as * by _time, host '
techniques:
- persistence:boot or logon initialization scripts:logon script (windows)
- privilege-escalation:boot or logon initialization scripts:logon script (windows)
technique_id:
- T1037.001
data_category:
- PowerShell logs
references:
- https://blog.morphisec.com/cobalt-gang-2.0

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_powershell` TERM(EventCode=4104) (TERM(reg) OR "reg.exe") TERM(add) TERM(UserInitMprLogonScript)

Stage 2: table

| table _time, host, user process, process_*, singature_id

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
  • 4104 corpus 268 (splunk 268)

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
1TERM
1reg
1"reg.exe"
1TERM
1add
1TERM
1UserInitMprLogonScript