Malicious PDF — malware analysis report

Static analysis result for SHA-256 83d46d4c8d229dcf…

MALICIOUS

PDF

3.9 KB
MD5: 536dc030c10810ab68c26ef079eea456 SHA-1: f83f9a9861171551af6d07b24770ddf3c2bcf325 SHA-256: 83d46d4c8d229dcff37da449c48683de5f1b697a3370bb7e98911e70c188ec81
112 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious JavaScript

The critical ClamAV detection 'Pdf.Exploit.Agent-36178' and multiple PDF-specific heuristics indicate this is a malicious PDF. The presence of embedded JavaScript, decoded using fromCharCode and potentially obfuscated with ASCIIHexDecode and ASCII85Decode filters, strongly suggests the execution of a malicious script. The script's exact function is unclear due to obfuscation, but it is likely designed to download and execute a secondary payload or exploit a vulnerability within the PDF reader.

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