Malicious PDF — malware analysis report

Static analysis result for SHA-256 774ad19117590234…

MALICIOUS

PDF

421.6 KB Created: 2010-11-29 10:29:36 Authoring application: FPDF 1.6
MD5: 2624b10ce050529850c041b991b0e134 SHA-1: e339137d269a20599e4b420110e50b5d9e2a27f3 SHA-256: 774ad19117590234584a518d3d0efda3d9b0cd4ba24be2c45ed108576aa450fb
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 and utilizes XFA forms, triggering heuristics related to PDF JavaScript exploits. The ML classifier strongly indicates maliciousness. While the embedded URLs are benign, the presence of exploit-related JavaScript suggests the document is designed to execute arbitrary code, likely for downloading and running a second-stage payload.

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/