Suspicious High IntegrityLevel Conhost Legacy Option

Hunt Hypothesis

ForceV1 asks for information directly from the kernel space. Conhost connects to the console application. High IntegrityLevel means the process is running with elevated privileges, such as an Administ

Detection Rule

Sigma (Original)

title: Suspicious High IntegrityLevel Conhost Legacy Option
id: 3037d961-21e9-4732-b27a-637bcc7bf539
status: test
description: ForceV1 asks for information directly from the kernel space. Conhost connects to the console application. High IntegrityLevel means the process is running with elevated privileges, such as an Administrator context.
references:
    - https://cybercryptosec.medium.com/covid-19-cyber-infection-c615ead7c29
    - https://thedfirreport.com/2022/04/04/stolen-images-campaign-ends-in-conti-ransomware/
    - https://learn.microsoft.com/en-us/windows/win32/secauthz/mandatory-integrity-control
author: frack113
date: 2022-12-09
modified: 2024-12-01
tags:
    - attack.stealth
    - attack.t1202
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        IntegrityLevel:
            - 'High'
            - 'S-1-16-12288'
        CommandLine|contains|all:
            - 'conhost.exe'
            - '0xffffffff'
            - '-ForceV1'
    condition: selection
falsepositives:
    - Very Likely, including launching cmd.exe via Run As Administrator
level: informational

KQL (Azure Sentinel)

imProcessCreate
| where (TargetProcessIntegrityLevel in~ ("High", "S-1-16-12288")) and (TargetProcessCommandLine contains "conhost.exe" and TargetProcessCommandLine contains "0xffffffff" and TargetProcessCommandLine contains "-ForceV1")

Required Data Sources

False Positive Guidance

• Very Likely, including launching cmd.exe via Run As Administrator

MITRE ATT&CK Context

• Technique: T1202 — T1202

References

• https://cybercryptosec.medium.com/covid-19-cyber-infection-c615ead7c29
• https://thedfirreport.com/2022/04/04/stolen-images-campaign-ends-in-conti-ransomware/
• https://learn.microsoft.com/en-us/windows/win32/secauthz/mandatory-integrity-control
• SigmaHQ Rule