Malicious PDF — malware analysis report

Static analysis result for SHA-256 4148f652442c9227…

MALICIOUS

PDF

3.9 KB
MD5: de7a708c8078a998457ac6c85090171c SHA-1: d4fd2f059fcc3a21552a72f1390c2b96dc2d1698 SHA-256: 4148f652442c922770a9d3adc90b24819d3cfb2ea2a4df072b9278580aa62e7d
142 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically detecting a PDF exploit. Heuristics indicate the presence of JavaScript actions and embedded JS streams, which are decoded using ASCIIHexDecode and ASCII85Decode filters. The ML classifier's high confidence score and the ClamAV detection strongly suggest this is an exploit document. The document body was unreadable, but the presence of exploit-related filters and JavaScript points to an attack pattern aimed at leveraging a PDF vulnerability.

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