Malicious PDF — malware analysis report

Static analysis result for SHA-256 9128cf9e205a857d…

MALICIOUS

PDF

3.9 KB
MD5: a2095592b31709a3bbb3639436d6e396 SHA-1: af8f8ac0ab9ba64b39fced84b67973c3a90c1004 SHA-256: 9128cf9e205a857d80e4f4ff587baf396fd9e4af1f01335294d231cf27e541c9
142 Risk Score

Malware Insights

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

The file is a PDF identified by ClamAV as 'Pdf.Exploit.Agent-36178'. Heuristics indicate the presence of JavaScript, string decoding functions, and filters commonly used in PDF exploits. The ML classifier strongly flags this as malicious. While no document body text was readable, the combination of exploit indicators and the ML score suggests the PDF is designed to deliver a second-stage payload.

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