Malicious PDF — malware analysis report

Static analysis result for SHA-256 c43992e0f8b13ff7…

MALICIOUS

PDF

3.9 KB
MD5: a9060bf90cf9f6f96eb919028c85417e SHA-1: 6e8252451c162f6679f024a081c935ae0545bb74 SHA-256: c43992e0f8b13ff755b010d1bdd742889f9e0e4fc21bc7ff6c8e313673f0806a
142 Risk Score

Malware Insights

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

The file is a PDF that triggered a high-confidence ML classifier and a critical ClamAV detection for Pdf.Exploit.Agent-36178. Static analysis revealed multiple PDF-specific heuristics indicating obfuscation and potential exploit activity, including the use of JavaScript, ASCIIHexDecode, and ASCII85Decode filters. The presence of these indicators strongly suggests the PDF is intended to exploit a vulnerability and likely download or 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