Malicious PDF — malware analysis report

Static analysis result for SHA-256 76c1acf39df8e2a6…

MALICIOUS

PDF

131.2 KB Created: 2010-11-29 10:29:36 Authoring application: FPDF 1.6
MD5: b48ead2c9b55ee9cb6a8bedbed4110d5 SHA-1: c6e33e0c14614673bd88e18569ab78918024a235 SHA-256: 76c1acf39df8e2a6ca320ba980ce49684bc059576a5f3b1fca15f59ca20ebd62
136 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript and utilizes XFA forms, which are indicators of exploitability. The ML classifier strongly suggests malicious intent. The JavaScript is likely used to exploit a client-side vulnerability for code execution, and the presence of PDF-specific exploit indicators further supports this. The document was likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 6

  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/2.6/
    • http://www.xfa.org/schema/xfa-template/2.6/