Malicious PDF — malware analysis report

Static analysis result for SHA-256 235759c9fe932a8c…

MALICIOUS

PDF

33.6 KB
MD5: ab36aca4d8cac3a5d32ae48dfe151f91 SHA-1: 00d5bf0fe729d6d7e09d1602e0455d13fa4268b2 SHA-256: 235759c9fe932a8ccd9f718c5a06943176f86d073fed5ceaa3d621b6c6defb74
74 Risk Score

Malware Insights

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

The PDF sample contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The presence of ASCIIHexDecode and ASCII85Decode filters, often used for obfuscation in malicious PDFs, further supports this. The ML classifier strongly flags this PDF as malicious. The embedded JavaScript is likely responsible for exploiting a vulnerability within the PDF reader to execute malicious code, potentially leading to further stages of an attack.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • ASCII85Decode filter (with exploit indicators) low PDF_FILTER_85
    ASCII85 encoding filter present alongside exploit delivery indicators — uncommon outside of obfuscation