Emerging Threathighexperimental

Exploitation Activity of CVE-2025-59287 - WSUS Deserialization

Detects cast exceptions in Windows Server Update Services (WSUS) application logs that highly indicate exploitation attempts of CVE-2025-59287, a deserialization vulnerability in WSUS.

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

Launch

Swachchhanda Shrawan Poudel (Nextron Systems)Created Fri Oct 31e5f66e87-7d6b-404f-92fe-7aa67814b5cd2025

Emerging Threat

Active Threat

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

Log Source

Windowsapplication

ProductWindows← raw: windows

Serviceapplication← raw: application

Detection Logic

detection:
    selection:
        Provider_Name: 'Windows Server Update Services'
        EventID: 7053
        Data|contains|all:
           # Indicators of untrusted deserialization exploitation attempts
           # https://github.com/pwntester/ysoserial.net/issues/114
            - 'System.InvalidCastException'
            - 'System.Windows.Data.ObjectDataProvider'
            - 'Unable to cast object of type'
            - 'System.Windows.Media.Brush'
    condition: selection