Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f2f3f77b6629064…

MALICIOUS

PDF

7.0 KB
MD5: da981d3c4344cdce3ee4fb0553be09df SHA-1: 419b299ad4b9277ac0a4fcfdf2fd8ba6122b2879 SHA-256: 5f2f3f77b66290648b7535924bfff22233ee16e31a270a51089c962089106079
76 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and utilizes filters like ASCIIHexDecode and ASCII85Decode, which are commonly used to obfuscate malicious code within PDF documents. The ML classifier strongly indicates maliciousness, suggesting the JavaScript is designed to exploit a client execution vulnerability. The presence of JavaScript points to T1059.007, and the exploitation of a vulnerability aligns with T1203. Given it's a file, T1566.001 is a likely initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

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