Sigma rule: Explorer Process Tree Break

Rule

Title

Explorer Process Tree Break

Status

test

Level

medium

Author

Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems), @gott_cyber

Date

2019-06-29

Modified

2025-10-31

File

rules/windows/process_creation/proc_creation_win_explorer_break_process_tree.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a command line process that uses explorer.exe to launch arbitrary commands or binaries,
which is similar to cmd.exe /c, only it breaks the process tree and makes its parent a new instance of explorer spawning from "svchost"

Log source

product

windows

category

process_creation

Detection

# Note: See CLSID_SeparateMultipleProcessExplorerHost in the registry for reference
selection_factory:
    CommandLine|contains: '/factory,{75dff2b7-6936-4c06-a8bb-676a7b00b24b}' # This will catch, the new explorer spawning which indicates a process/tree break. But you won't be able to catch the executing process. For that you need historical data
selection_root:
    CommandLine|contains: 'explorer.exe'
    CommandLine|contains|windash: ' /root,'
    # There exists almost infinite possibilities to spawn from explorer. The "/root" flag is just an example
    # It's better to have the ability to look at the process tree and look for explorer processes with "weird" flags to be able to catch this technique.
condition: 1 of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.stealth
• attack.t1036

MITRE ATT&CK ids this rule names

• T1036

References

• https://twitter.com/CyberRaiju/status/1273597319322058752
• https://twitter.com/bohops/status/1276357235954909188?s=12
• https://twitter.com/nas_bench/status/1535322450858233858
• https://securityboulevard.com/2019/09/deobfuscating-ostap-trickbots-34000-line-javascript-downloader/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_explorer_break_process_tree.yml