Malicious PDF — malware analysis report

Static analysis result for SHA-256 93c5057ec47fb259…

MALICIOUS

PDF

3.9 KB
MD5: ca62686a818aa1f8c83d3005b1bc34ab SHA-1: cba2ea7041facc5262de8add530b1db80deed5d1 SHA-256: 93c5057ec47fb259f4b70defaf3e0d6ab0b6bbf5c18a3f3de45b733ecc6c8690
142 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1204 User Execution

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically detecting it as Pdf.Exploit.Agent-36178. The presence of PDF_JAVASCRIPT, PDF_JS, and PDF_FILTER heuristics indicates that the file contains embedded JavaScript, likely obfuscated using ASCIIHexDecode and ASCII85Decode filters, which is a common technique for exploiting PDF vulnerabilities. The script's purpose is presumed to be downloading and executing a second-stage 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