Malicious PDF — malware analysis report

Static analysis result for SHA-256 12cb15db84a7b8ca…

MALICIOUS

PDF

2.30 MB Created: 2009-12-21 16:55:35 +08:00 Authoring application: Acrobat PDFMaker 7.0ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿcer(Acrobat Distiller 7.0 (Windows) (via Acrobat Distiller 7.0 (Windows))
MD5: c603a9689c15e56391a121325ef781c0 SHA-1: bd5ff2864d44d2268fb3b71103847cda8abdd605 SHA-256: 12cb15db84a7b8cad1bdab5902e5b19283ee9ab9c563176afed88291ea0375a7
252 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF sample contains embedded JavaScript that leverages the CVE-2009-4324 vulnerability (media.newPlayer) to achieve code execution. The JavaScript is heavily obfuscated and appears to be a downloader for a second-stage payload, indicated by the 'generic stage recovery' heuristic and the presence of multiple deobfuscated JavaScript streams. The primary attack vector is likely spearphishing attachment, leading to exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 9

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (matched in decompressed stream)
  • 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)
  • Generic recovered JavaScript exploit stage high PDF_GENERIC_STAGE_RECOVERY
    Bounded static stage recovery exposed hidden JavaScript through generic transforms such as null-byte collapse, percent decoding, marker replacement, arithmetic character codes, fromCharCode, numeric arrays, numeric-array minus-key decoders, alphabet-index arrays, /Producer half-difference metadata arrays, hex literals, marker-stripped Base64 literals, custom 6-bit XOR table decoders, or repeated-marker hex carriers. This rule is emitted only when the recovered stage contains exploit-like Acrobat JavaScript or shellcode markers.
  • 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/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/
    • http://ns.adobe.com/photoshop/1.0/

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0043_000.js
6a4feff50242ca48bccb7b8303874c63d44c492cea43499d20ce94d354dc031d
pdf-javascript-stream PDF /JS object 43 at offset 0x2430 2172 bytes
javascript_obj0043_001.js
72a7a81874bc825243697fb1380a9dc969da68bf826f90ff5241fdd360dd07a9
pdf-javascript-stream PDF /JS object 43 at offset 0x2465 6463 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 20 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
generic_stage_recovery_000.js
16ae11897d85015a75a4476aa5d780ff0fb25880746f1a6e954a1c4f5329200c
deobfuscated-js generic stage recovery marker-XX-to-%u from combined JavaScript objects at offset 0x2430 5838 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 20 eval/decoder/string-building token(s).
combined_document_js_000.js
6b274891890bf0d519e3384adb17e8bb7394a4452b3b364e01a340896daea0d1
deobfuscated-js combined document JavaScript streams at offset 0x2430 8636 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 20 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).