Detection rules › Sigma
Potential Proxy Execution Via Explorer.EXE From Shell Process
Detects the creation of a child "explorer.exe" process from a shell like process such as "cmd.exe" or "powershell.exe". Attackers can use "explorer.exe" for evading defense mechanisms by proxying the execution through the latter. While this is often a legitimate action, this rule can be use to hunt for anomalies. Muddy Waters threat actor was seeing using this technique.
Known false positives
- Legitimate explorer.exe run from a shell host like "cmd.exe" or "powershell.exe"
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
| Security-Auditing | Event ID 4688: A new process has been created. |
Rule body
title: Potential Proxy Execution Via Explorer.EXE From Shell Process
id: 9eb271b9-24ae-4cd4-9465-19cfc1047f3e
status: test
description: |
Detects the creation of a child "explorer.exe" process from a shell like process such as "cmd.exe" or "powershell.exe".
Attackers can use "explorer.exe" for evading defense mechanisms by proxying the execution through the latter.
While this is often a legitimate action, this rule can be use to hunt for anomalies.
Muddy Waters threat actor was seeing using this technique.
references:
- https://twitter.com/CyberRaiju/status/1273597319322058752
- https://app.any.run/tasks/9a8fd563-4c54-4d0a-9ad8-1fe08339cbc3/
author: Furkan CALISKAN, @caliskanfurkan_, @oscd_initiative
date: 2020-10-05
modified: 2024-06-21
tags:
- attack.stealth
- attack.t1218
- detection.threat-hunting
logsource:
category: process_creation
product: windows
detection:
selection:
ParentImage|endswith:
- '\cmd.exe'
- '\powershell.exe'
- '\pwsh.exe'
Image|endswith: '\explorer.exe'
CommandLine|contains: 'explorer.exe'
condition: selection
falsepositives:
- Legitimate explorer.exe run from a shell host like "cmd.exe" or "powershell.exe"
level: low
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
ParentImage|endswith:
- '\cmd.exe'
- '\powershell.exe'
- '\pwsh.exe'
Image|endswith: '\explorer.exe'
CommandLine|contains: 'explorer.exe'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match value:"explorer.exe" |
Image | ends_with |
| field:"Image" kind:ends_with value:"\explorer.exe" |
ParentImage | ends_with |
| field:"ParentImage" kind:ends_with |