Malicious PDF — malware analysis report

Static analysis result for SHA-256 cefea5263f7ac59d…

MALICIOUS

PDF

3.9 KB
MD5: 2c96d787fb7ff1ab3902b81eb0100001 SHA-1: 18ea90e8c2624035cc5803bff43e2b42e39e6a96 SHA-256: cefea5263f7ac59defb58baf2eb88c8973d42e7e1078a4754cbbf284c2d62369
142 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically detecting it as Pdf.Exploit.Agent-36178. Heuristics indicate the presence of JavaScript actions and embedded JS streams, along with filters like ASCIIHexDecode and ASCII85Decode, which are commonly used in PDF exploits. The ML classifier output of 0.999984 strongly suggests malicious intent, likely involving the execution of embedded JavaScript to exploit a vulnerability.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • ClamAV: Pdf.Exploit.Agent-36178 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36178
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • ASCII85Decode filter (with exploit indicators) low PDF_FILTER_85
    ASCII85 encoding filter present alongside exploit delivery indicators — uncommon outside of obfuscation