Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f669836a3d09628…

MALICIOUS

PDF

4.0 KB
MD5: b32f8968f7aa46eb4d6dfd9087e16725 SHA-1: 52fa1b46bb469a3ec31d1fdba92bf909ff85d7a4 SHA-256: 8f669836a3d09628865814f3c8b42ddce859398a84d1d33c1df835a44149e505
142 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by ClamAV and a machine learning classifier. Multiple PDF-specific heuristics indicate the presence of obfuscated JavaScript and exploit-related filters, suggesting it attempts to leverage a known PDF vulnerability. The ML classifier's high confidence score further supports this assessment. No document body text was available for analysis, but the combination of heuristics and detection names strongly indicates an exploit attempt.

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