Malicious PDF — malware analysis report

Static analysis result for SHA-256 9890dfff15f84734…

MALICIOUS

PDF

3.9 KB
MD5: 31ce1b7528f7135f6ddf2fd1aaf4da5c SHA-1: ffa55095012c3c8372513e90ecf33be6e4e16852 SHA-256: 9890dfff15f8473415e576b8e939fe56b4a8671418636d42dfbd7c3c0673a28a
142 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically identifying it as Pdf.Exploit.Agent-36178. Heuristics indicate the presence of JavaScript, embedded JS streams, and the use of ASCIIHexDecode and ASCII85Decode filters, which are commonly used in PDF exploits. The ML classifier's high confidence score further supports the malicious nature of the file. No document body text was available for analysis, but the technical indicators strongly suggest an exploit delivery mechanism.

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