Malicious PDF — malware analysis report

Static analysis result for SHA-256 388926bbecbdd1fd…

MALICIOUS

PDF

5.2 KB
MD5: 68546c29f3d3f7a6e2cc56fb81047534 SHA-1: 94ec76aed51c544cc0b370c7b3aa1e2d437f373f SHA-256: 388926bbecbdd1fd9efdde635090ab3a580f83d7a5add25e5b2856d103b17528
114 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Script Execution: JavaScript T1204.002 Malicious File: 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 String.fromCharCode, suggests obfuscation techniques commonly used to hide malicious code. ClamAV also detected this as Pdf.Exploit.Agent-36178, confirming its malicious nature. The exact payload or exploit targeted is not discernible from the provided evidence, but the presence of JavaScript points to an attempt to execute arbitrary code.

Heuristics 7

  • 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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.