Malicious PDF — malware analysis report

Static analysis result for SHA-256 d95cb23570c00968…

MALICIOUS

PDF

3.8 KB
MD5: e57d36a6f106587400371f3f4dd48b75 SHA-1: cf6ddb868dafa874298a24f0ab410c8f286d8a1f SHA-256: d95cb23570c009689b4154f25eac4763830eb55045fc21ff8eabf4cc6ce2c6b4
142 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by a machine learning classifier and ClamAV, indicating it contains an exploit. Several heuristics point to the presence of embedded and obfuscated JavaScript, likely used to deliver a second-stage payload. The use of PDF-specific filters like ASCIIHexDecode and ASCII85Decode, combined with JavaScript actions, is a common technique for exploiting PDF vulnerabilities.

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