Malicious PDF — malware analysis report

Static analysis result for SHA-256 10999e059dde1cce…

MALICIOUS

PDF

52.6 KB Created: 2009-06-06 21:05:54 +08:00 Authoring application: Acrobat Distiller 7.0 (Windows)
MD5: 96f761e73d8393a1a96a72779e14e42f SHA-1: 9293b068891da22cf8cb6bef3f1820ceb8f014d1 SHA-256: 10999e059dde1cce21480582a4196b51093b86f541c06b89ad2e48fde75e5da9
152 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 that is heavily obfuscated and utilizes unescape() calls, indicating an attempt to conceal malicious code. The ML classifier and PDF JavaScript exploit cluster heuristics strongly suggest this is a malicious document. The script likely downloads and executes a second-stage payload, which is a common technique for malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/iX/1.0/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/pdfx/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://purl.org/dc/elements/1.1/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0022_000.js
0aaad551850424ba802fd4bd6dbfdadf6e6d74091c1e34d81f286071bfeb4e44
pdf-javascript-stream PDF /JS object 22 at offset 0xBB31 6046 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 22 eval/decoder/string-building token(s).