Malicious PDF — malware analysis report

Static analysis result for SHA-256 28ffad2073d1f828…

MALICIOUS

PDF

3.9 KB
MD5: cecc8f3329268ddbed194358b0b691aa SHA-1: 6f1af19b075e0c28aa3e451ebaa14de84fd784e4 SHA-256: 28ffad2073d1f82817dfbb1c77f8fa890e5e2da81019b8a41682769bac8d47e2
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 multiple heuristics and a machine learning classifier, with ClamAV providing a specific detection name (Pdf.Exploit.Agent-36178). The presence of JavaScript actions, embedded JS streams, and the use of ASCIIHexDecode and ASCII85Decode filters strongly indicate an exploit attempt within the PDF structure. The ML classifier's high confidence score further supports the malicious nature of the file.

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