Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6fde16108c7730e…

MALICIOUS

PDF

3.8 KB
MD5: 9fb57896e9e1b40abc46f96f89c73a49 SHA-1: f89823b9be627a0ec36b8389c17b37d515c68b9e SHA-256: b6fde16108c7730e79d929c2d687f2e61bff6f0e6cb3b3b2f481f68caa8ae0ae
142 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious JavaScript

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The presence of PDF_FILTER_HEX and PDF_FILTER_85 filters, along with the ML_NYX_PDF_MALICIOUS and CLAMAV_DETECTION firings, strongly suggests this is a malicious PDF exploiting a known vulnerability. The JavaScript is likely used to download and execute a second-stage 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