Emerging Threatmediumexperimental

Suspicious CrushFTP Child Process

Detects suspicious child processes spawned by the CrushFTP service that may indicate exploitation of remote code execution vulnerabilities such as CVE-2025-31161, where attackers can achieve RCE through crafted HTTP requests. The detection focuses on commonly abused Windows executables (like powershell.exe, cmd.exe etc.) that attackers typically use post-exploitation to execute malicious commands.

Convert In Phoenix Studio

Open this Sigma rule in the converter with the YAML preloaded and ready for backend selection.

Launch

Craig Sweeney, Matt Anderson, Jose Oregon, Tim Kasper, Faith Stratton, Samantha Shaw, Swachchhanda Shrawan Poudel (Nextron Systems)Created Thu Apr 10459628e3-1b00-4e9b-9e5b-7da8961aea352025

Emerging Threat

Active Threat

Developed to detect an active or emerging threat. Prioritize investigation of any alerts and correlate with threat intelligence.

Log Source

WindowsProcess Creation

ProductWindows← raw: windows

CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic

detection:
    selection_parent:
        ParentImage|endswith: '\crushftpservice.exe'
    selection_child:
        Image|endswith:
            - '\bash.exe'
            - '\cmd.exe'
            - '\cscript.exe'
            - '\mshta.exe'
            - '\powershell.exe'
            - '\powershell_ise.exe'
            - '\pwsh.exe'
            - '\sh.exe'
            - '\wscript.exe'
    condition: all of selection_*