Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b5fc465db78a458…

MALICIOUS

PDF

3.8 KB
MD5: 15493bc5959c52b5751b00b53f1074ad SHA-1: 5c9b21e1e8c8b293320ec4f7e24be6e9ba1fe2cf SHA-256: 3b5fc465db78a4582903c529864d91c647a5fc41cf4a2a3167033b18acc36f2a
142 Risk Score

Malware Insights

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

The file is a PDF identified by ClamAV as Pdf.Exploit.Agent-36178. Heuristics indicate the presence of JavaScript, string decoding functions, and hex/ASCII85 filters, all commonly used in PDF exploits. The ML classifier strongly supports a malicious classification. While no specific script content is available, the combination of these indicators points to a likely exploit delivery mechanism.

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