Sigma rule: Conhost Spawned By Uncommon Parent Process

Rule

Title

Conhost Spawned By Uncommon Parent Process

Status

test

Level

medium

Author

Tim Rauch, Elastic (idea)

Date

2022-09-28

Modified

2025-03-06

File

rules/windows/process_creation/proc_creation_win_conhost_uncommon_parent.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects when the Console Window Host (conhost.exe) process is spawned by an uncommon parent process, which could be indicative of potential code injection activity.

Log source

product

windows

category

process_creation

Detection

selection:
    Image|endswith: '\conhost.exe'
    ParentImage|endswith:
        - '\explorer.exe'
        # - '\csrss.exe'  # Legitimate parent as seen in EchoTrail https://www.echotrail.io/insights/search/csrss.exe
        # - '\ctfmon.exe'  # Seen several times in a testing environment
        # - '\dllhost.exe'  # FP on clean system from grandparent 'svchost.exe -k DcomLaunch -p'
        - '\lsass.exe'
        - '\regsvr32.exe'
        - '\rundll32.exe'
        - '\services.exe'
        - '\smss.exe'
        - '\spoolsv.exe'
        - '\svchost.exe'
        - '\userinit.exe'
        # - '\wermgr.exe'  # Legitimate parent as seen in EchoTrail https://www.echotrail.io/insights/search/wermgr.exe
        - '\wininit.exe'
        - '\winlogon.exe'
filter_main_svchost:
    ParentCommandLine|contains:
        - '-k apphost -s AppHostSvc'
        - '-k imgsvc'
        - '-k localService -p -s RemoteRegistry'
        - '-k LocalSystemNetworkRestricted -p -s NgcSvc'
        - '-k NetSvcs -p -s NcaSvc'
        - '-k netsvcs -p -s NetSetupSvc'
        - '-k netsvcs -p -s wlidsvc'
        - '-k NetworkService -p -s DoSvc'
        - '-k wsappx -p -s AppXSvc'
        - '-k wsappx -p -s ClipSVC'
        - '-k wusvcs -p -s WaaSMedicSvc'
filter_optional_dropbox:
    ParentCommandLine|contains:
        - 'C:\Program Files (x86)\Dropbox\Client\'
        - 'C:\Program Files\Dropbox\Client\'
condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.t1059

MITRE ATT&CK ids this rule names

• T1059

References

• https://www.elastic.co/guide/en/security/current/conhost-spawned-by-suspicious-parent-process.html

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_uncommon_parent.yml