Malicious PDF — malware analysis report

Static analysis result for SHA-256 fdf540110be305b5…

MALICIOUS

PDF

3.8 KB
MD5: ff650235a8df458862ccc7e568378fdf SHA-1: 526929be7b13ae0c1e762023b74cab664e8a7629 SHA-256: fdf540110be305b5dd79034252026e4a66cc699fd2fad6b2de61b2cd649706cd
112 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Script Execution: JavaScript T1204.002 Malicious File Execution: Malicious JavaScript

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The use of ASCIIHexDecode and ASCII85Decode filters, along with the ClamAV detection of 'Pdf.Exploit.Agent-36178', strongly suggests the exploitation of a PDF vulnerability to execute this JavaScript. The script is likely designed to download and execute a second-stage payload.

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