Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b3bc8660fe8a1d5…

MALICIOUS

PDF

3.9 KB
MD5: fb78cbd569b468f24ac79590c2a988d7 SHA-1: 32177741698cf7c885291fa4bd51131216a3ba37 SHA-256: 2b3bc8660fe8a1d511afc5b1e473515c0ff5f0674c01d0d5b9af9c3abd0ce376
142 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The ML classifier and ClamAV detection strongly suggest malicious intent, specifically identifying it as Pdf.Exploit.Agent-36178. The presence of JavaScript actions and decoded streams using ASCIIHexDecode and ASCII85Decode filters points towards an exploit attempting to execute arbitrary code.

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