Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a66e6ab4719bc0b…

MALICIOUS

PDF

3.9 KB
MD5: 3aa102952b3db5337369767747d2b2b1 SHA-1: bce094b19772313bd69fcd9cdf8e836a31ce53b4 SHA-256: 9a66e6ab4719bc0bcfd3b53992c4d4c6f0d65065294f31dc291508018cb7fc25
112 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The presence of ASCIIHexDecode and ASCII85Decode filters, flagged with exploit indicators, suggests an attempt to obfuscate malicious code. ClamAV detection as 'Pdf.Exploit.Agent-36178' further confirms its malicious nature. The embedded JavaScript is likely responsible for exploiting a vulnerability within the PDF reader to download and execute a secondary payload.

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