Detection rules › Splunk

Non-MSIExec .msi Installation (PowerShell)

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

This use case detects methods used to install .msi files without the use of msiexec.exe

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

id: '18115.30466'
title: Non-MSIExec .msi Installation
description: 'This use case detects methods used to install .msi files without the
  use of msiexec.exe. Atomics T1218.007 Test #5 Atomics T1218.007 Test #6 Atomics
  T1218.007 Test #7 Atomics T1218.007 Test #8'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR
  "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") (TERM(install) OR
  TERM(/i)) ".msi" | regex process_name!="(?i)msiexec" | table _time, host, user parent_*,
  process, process_* | bin span=1s | stats values(*) as * by _time, host '
techniques:
- execution:command and scripting interpreter
technique_id: 
- T1059
data_category:
- PowerShell logs
references:
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.007/T1218.007.md

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") (TERM(install) OR TERM(/i)) ".msi"

Stage 2: regex

| regex process_name!="(?i)msiexec"

Stage 3: table

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

Stage 4: bucket

| bin span=1s

Stage 5: stats

| stats values(*) as * by _time, host

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
process_nameregex_match"(?i)msiexec"

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)

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>4103<"
1TERM
1"<EventID>4104<"
1TERM
1install
1"/i"
1".msi"