Malicious PDF — malware analysis report

Static analysis result for SHA-256 ded91a929a0e7415…

MALICIOUS

PDF

3.9 KB
MD5: c4b539e31c9abfee2942f85660538cf8 SHA-1: df88c54e624613bdc4bb3464d925df9a29d539e4 SHA-256: ded91a929a0e74150ca0b9117a1cf529348e87cc79f09dc07dfffc8413ef4bbf
142 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1566.002 Spearphishing Attachment T1059.001 PowerShell

The file is a PDF identified by ClamAV as 'Pdf.Exploit.Agent-36178'. Heuristics indicate the presence of JavaScript, including the use of String.fromCharCode and various PDF filters (ASCIIHexDecode, ASCII85Decode) often associated with exploit delivery. The ML classifier strongly flags this PDF as malicious. While no specific document body text is available for content analysis, the combination of JavaScript and exploit-related filters suggests the PDF's primary function is to exploit a vulnerability to download and execute a secondary payload.

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