Sigma rule: Potentially Suspicious Child Processes Spawned by ConHost

Rule

Title

Potentially Suspicious Child Processes Spawned by ConHost

Status

experimental

Level

high

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-02-05

File

rules/windows/process_creation/proc_creation_win_conhost_susp_winshell_child_process.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects suspicious child processes related to Windows Shell utilities spawned by `conhost.exe`, which could indicate malicious activity using trusted system components.

Log source

product

windows

category

process_creation

Detection

selection_parent:
    ParentImage|endswith: '\conhost.exe'
selection_child:
    - Image|endswith:
          - '\cmd.exe'             # Windows Command Prompt
          - '\cscript.exe'         # Windows Script Host (used for scripting exploits)
          - '\mshta.exe'           # MSHTA (HTML Application Host, often abused)
          - '\powershell_ise.exe'  # PowerShell ISE
          - '\powershell.exe'      # Windows PowerShell
          - '\pwsh.exe'            # PowerShell Core
          - '\regsvr32.exe'        # Windows Registry Server (commonly used for exploits)
          - '\wscript.exe'         # Windows Script Host (for executing scripts)
    - OriginalFileName:
          - 'cmd.exe'
          - 'cscript.exe'
          - 'mshta.exe'
          - 'powershell_ise.exe'
          - 'powershell.exe'
          - 'pwsh.dll'
          - 'regsvr32.exe'
          - 'wscript.exe'
condition: all of selection_*

False positives (as the rule lists them)

• Legitimate administrative tasks using `conhost.exe` to spawn child processes such as `cmd.exe`, `powershell.exe`, or `regsvr32.exe`.

Tags

• attack.stealth
• attack.t1202
• attack.t1218

MITRE ATT&CK ids this rule names

• T1202
• T1218

Related rules

• 7dc2dedd-7603-461a-bc13-15803d132355 (similar)

References

• https://tria.ge/241015-l98snsyeje/behavioral2

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_conhost_susp_winshell_child_process.yml