Malicious PDF — malware analysis report

Static analysis result for SHA-256 bce7d4c39361acbe…

MALICIOUS

PDF

3.9 KB
MD5: bb7a77386d19ce9459235a27d014ce2f SHA-1: fb8f1680c310e82302da7ddf132017e6932782d7 SHA-256: bce7d4c39361acbedc5faa63762f59d97c558f204ebce01309490c97b28f02b8
142 Risk Score

Malware Insights

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

The file is a PDF that has been flagged by multiple heuristics and a machine learning classifier as malicious. It contains embedded JavaScript, which is likely used to exploit a vulnerability within the PDF reader. The presence of PDF_JAVASCRIPT, PDF_JS, and PDF_FROMCHARCODE rules, along with the ML_NYX_PDF_MALICIOUS and CLAMAV_DETECTION firings, strongly indicates an exploit attempt. The specific exploit is likely Agent-36178, as detected by ClamAV.

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