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Detection rules › Sigma

Potentially Suspicious Child Process Of ClickOnce Application

Status
test
Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects potentially suspicious child processes of a ClickOnce deployment application

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation
Security-AuditingEvent ID 4688A new process has been created.

Rule body yaml

title: Potentially Suspicious Child Process Of ClickOnce Application
id: 67bc0e75-c0a9-4cfc-8754-84a505b63c04
status: test
description: Detects potentially suspicious child processes of a ClickOnce deployment application
references:
    - https://posts.specterops.io/less-smartscreen-more-caffeine-ab-using-clickonce-for-trusted-code-execution-1446ea8051c5
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-06-12
tags:
    - attack.execution
    - attack.stealth
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|contains: '\AppData\Local\Apps\2.0\'
        Image|endswith:
            # Add more suspicious processes
            - '\calc.exe'
            - '\cmd.exe'
            - '\cscript.exe'
            - '\explorer.exe'
            - '\mshta.exe'
            - '\net.exe'
            - '\net1.exe'
            - '\nltest.exe'
            - '\notepad.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\reg.exe'
            - '\regsvr32.exe'
            - '\rundll32.exe'
            - '\schtasks.exe'
            - '\werfault.exe'
            - '\wscript.exe'
    condition: selection
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ParentImage|contains: '\AppData\Local\Apps\2.0\'
    Image|endswith:
        # Add more suspicious processes
        - '\calc.exe'
        - '\cmd.exe'
        - '\cscript.exe'
        - '\explorer.exe'
        - '\mshta.exe'
        - '\net.exe'
        - '\net1.exe'
        - '\nltest.exe'
        - '\notepad.exe'
        - '\powershell.exe'
        - '\pwsh.exe'
        - '\reg.exe'
        - '\regsvr32.exe'
        - '\rundll32.exe'
        - '\schtasks.exe'
        - '\werfault.exe'
        - '\wscript.exe'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \calc.exe corpus 14 (sigma 14)
  • \cmd.exe corpus 134 (sigma 134)
  • \cscript.exe corpus 76 (sigma 76)
  • \explorer.exe corpus 17 (sigma 17)
  • \mshta.exe corpus 69 (sigma 69)
  • \net.exe corpus 50 (sigma 50)
  • \net1.exe corpus 48 (sigma 48)
  • \nltest.exe corpus 9 (sigma 9)
  • \notepad.exe corpus 11 (sigma 11)
  • \powershell.exe corpus 186 (sigma 186)
  • \pwsh.exe corpus 172 (sigma 172)
  • \reg.exe corpus 60 (sigma 60)
  • \regsvr32.exe corpus 68 (sigma 68)
  • \rundll32.exe corpus 103 (sigma 103)
  • \schtasks.exe corpus 57 (sigma 57)
  • \werfault.exe corpus 14 (sigma 14)
  • \wscript.exe corpus 78 (sigma 78)
ParentImagematch
  • \AppData\Local\Apps\2.0\