Malicious PDF — malware analysis report

Static analysis result for SHA-256 498c6995ed282902…

MALICIOUS

PDF

3.9 KB
MD5: b97a4b06b4fe87ad8c0138d9014c717e SHA-1: 3a32354e883b98d3b8b40b3a0cbfc9688dc1e9f9 SHA-256: 498c6995ed2829029b500c970c628ad407d7b0082c9a0899c0fd22ae73e484c5
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. ClamAV specifically identifies it as 'Pdf.Exploit.Agent-36178', indicating a known exploit within the PDF structure. The presence of JavaScript actions and embedded JS streams, combined with the use of ASCIIHexDecode and ASCII85Decode filters, strongly suggests an attempt to obfuscate and deliver an exploit payload. The ML classifier's high confidence score further supports this assessment.

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