Malicious PDF — malware analysis report

Static analysis result for SHA-256 d6434e09a4e53654…

MALICIOUS

PDF

3.9 KB
MD5: c36a4cbbf1953f86ac9050faf17e3403 SHA-1: b3c0519d007bd79256979761f0b9f8db516d9eee SHA-256: d6434e09a4e53654112f3bb435fae95c891dde5b220310615a6838936a3a38ca
142 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1059.001 Command and Scripting Interpreter: PowerShell

The file is a PDF identified as malicious by ClamAV and a machine learning classifier. Heuristics indicate the presence of JavaScript and the use of PDF-specific filters like ASCIIHexDecode and ASCII85Decode, often employed to obfuscate exploit code. The ML classifier's high confidence score further supports its malicious nature. The exact exploit and payload are not discernible from the provided evidence, but the techniques suggest an attempt to execute arbitrary code upon opening.

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