Detection rules › Splunk

Registry Entry Created - PowerShell (PowerShell)

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

Adversaries may interact with the Windows Registry to hide configuration information within Registry keys, remove information as part of cleaning up, or as part of other techniques to aid in persistence and execution. This use case detects PowerShell scripts or commands creating new registry entries.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1112 Modify Registry
Defense ImpairmentT1112 Modify Registry

References

Event coverage

Rule body yaml

id: '20185.35853'
title: Registry Entry Created - PowerShell
description: 'Adversaries may interact with the Windows Registry to hide configuration
  information within Registry keys, remove information as part of cleaning up, or
  as part of other techniques to aid in persistence and execution. This use case detects
  PowerShell scripts or commands creating new registry entries. '
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` ((EventCode=4104) OR "<EventID>4104<"
  OR (EventCode=4103) OR "<EventID>4103<") (TERM(New-Item) OR TERM(New-ItemProperty)
  OR TERM(Set-ItemProperty) OR TERM(sp) OR TERM(Set-Item) OR TERM(sip)) ("HKCU" OR
  "HKLM" OR "HKU" OR "HKEY_") | regex process="(?i)((New|Set)-Item(Property?)|sp|sip)\s+(-Path\s+?)(\"(HKCU|HKLM|HKU|HKEY_))"|
  table _time, host, user user, process, process_name | bin span=1s | stats values(*)
  as * by _time, host '
techniques:
- defense-evasion:modify registry
technique_id: 
- T1112
data_category:
- PowerShell logs
references:
- https://blog.sygnia.co/breaking-down-casbaneiro-infection-chain-part2?_ga=2.66949422.1638613298.1690290265-1923873697.1682517767
- https://gist.github.com/netbiosX/a114f8822eb20b115e33db55deee6692

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_powershell` ((EventCode=4104) OR "<EventID>4104<" OR (EventCode=4103) OR "<EventID>4103<") (TERM(New-Item) OR TERM(New-ItemProperty) OR TERM(Set-ItemProperty) OR TERM(sp) OR TERM(Set-Item) OR TERM(sip)) ("HKCU" OR "HKLM" OR "HKU" OR "HKEY_")

Stage 2: regex

| regex process="(?i)((New|Set)-Item(Property?)|sp|sip)\s+(-Path\s+?)(\"(HKCU|HKLM|HKU|HKEY_))"

Stage 3: table

| table _time, host, user user, process, process_name

Stage 4: bucket

| bin span=1s

Stage 5: 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
  • 4103 corpus 105 (splunk 105)
  • 4104 corpus 268 (splunk 268)
processregex_match
  • "(?i)((New|Set)-Item(Property?)|sp|sip)\s+(-Path\s+?)(\"(HKCU|HKLM|HKU|HKEY_))"

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
1"<EventID>4104<"
1"<EventID>4103<"
1"New-Item"
1"New-ItemProperty"
1"Set-ItemProperty"
1TERM
1sp
1"Set-Item"
1TERM
1sip
1"HKCU"
1"HKLM"
1"HKU"
1"HKEY_"