CISA releases malware analysis report associated with Microsoft SharePoint vulnerabilities

CISA published a Malware Analysis Report (MAR) with analysis and associated detection signatures on files related to Microsoft SharePoint vulnerabilities: CVE-2025-49704 [CWE-94: Code Injection], CVE-2025-49706 [CWE-287: Improper Authentication], CVE-2025-53770 [CWE-502: Deserialization of Untrusted Data], and CVE-2025-53771 [CWE-287: Improper Authentication].

Cyber threat actors have chained CVE-2025-49704 and CVE-2025-49706 (in an exploit chain publicly known as “ToolShell”) to gain unauthorized access to on-premises SharePoint servers.

CISA analyzed six files including two Dynamic Link-Library (.DLL), one cryptographic key stealer, and three web shells. Cyber threat actors could leverage this malware to steal cryptographic keys and execute a Base64-encoded PowerShell command to fingerprint host system and exfiltrate data.

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