Detection rules › Splunk
Suspicious Parent Process for msiexec.exe (Sysmon)
msiexec.exe is a Windows system component used to install and modify software packages using Windows Installer. Threat actors may abuse msiexec.exe to install malicious software or execute scripts, leveraging its legitimate appearance to bypass security measures and gain persistence on a targeted system as observed in FlawedGrace attacks. This use case detects executions of msiexec.exe with suspicious parent processes
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth |
References
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
id: '24143.44553'
title: Suspicious Parent Process for msiexec.exe
description: msiexec.exe is a Windows system component used to install and modify
software packages using Windows Installer. Threat actors may abuse msiexec.exe to
install malicious software or execute scripts, leveraging its legitimate appearance
to bypass security measures and gain persistence on a targeted system as observed
in FlawedGrace attacks. This use case detects executions of msiexec.exe with suspicious
parent processes. Living Off the Land Binary and Scripts (LOLBAS) (LOLBIN)
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<")
TERM(msiexec) OR "msiexec.exe" | regex parent_process_name="(?i)(spoolsv|powershell|pwsh|cmd|svchost|winlogon|taskhost|wininit)\.exe"
| table _time, host, user process, process_*, parent_process_name, parent_process_*
| bin span=1s | stats values(*) as * by _time, host '
techniques:
- defense-evasion:system binary proxy execution:msiexec
technique_id:
- T1218.007
data_category:
- Windows Sysmon
references:
- https://thedfirreport.com/2023/06/12/a-truly-graceful-wipe-out/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<") TERM(msiexec) OR "msiexec.exe"
Stage 2: regex
| regex parent_process_name="(?i)(spoolsv|powershell|pwsh|cmd|svchost|winlogon|taskhost|wininit)\.exe"
Stage 3: table
| table _time, host, user process, process_*, parent_process_name, parent_process_*
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
EventCode | eq |
| field:"EventID" kind:eq value:"1" |
parent_process_name | regex_match |
| field:"parent_process_name" kind:regex_match |
Search terms
These SPL tokens match against raw event text.
| Stage | Term |
|---|---|
| 1 | "<EventID>1<" |
| 1 | msiexec |
| 1 | "msiexec.exe" |