Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba4e127fa8a79237…

MALICIOUS

PDF

3.8 KB
MD5: b4fd4c4da5b850eb33a1941219b8b642 SHA-1: 2de0288488a6f911e14ecb75dcfd1783afe876a5 SHA-256: ba4e127fa8a7923709656464acbb65fc1fab03b8705a495d110e7fa67a8c4951
142 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1204.002 Malicious File: User Execution: Malicious Attachment

The file is identified as a malicious PDF by ClamAV and a machine learning classifier. Heuristics indicate the presence of JavaScript and the use of PDF filters like ASCIIHexDecode and ASCII85Decode, often employed to obfuscate exploit code. The ML classifier's high score further supports its malicious nature. While no document body or scripts were directly extracted, the combination of PDF-specific exploit indicators and high detection scores strongly suggests it's designed to exploit a vulnerability 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