Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a84c63a4606fd19…

MALICIOUS

PDF

421.6 KB Created: 2010-11-29 10:29:36 Authoring application: FPDF 1.6
MD5: 3a805b2c8bc0bb35f07b40e34fdf758b SHA-1: fef9510b48645d8c7224f711ae9e49d07dae9cab SHA-256: 0a84c63a4606fd19ccc84ad8ec980deebe996489c8d45a9ba6815f9dbf1eee1b
136 Risk Score

Malware Insights

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

The sample is a PDF file that contains embedded JavaScript, triggering heuristics related to PDF exploits and XFA forms. The ML classifier strongly indicates maliciousness. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, a common technique for initial compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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/