Malicious PDF — malware analysis report

Static analysis result for SHA-256 79d47fc40b5314b0…

MALICIOUS

PDF

154.8 KB Created: 2010-06-29 10:14:47 +08:00 Authoring application: Acrobat 编辑器 8.0 (via Adobe Acrobat 8.0)
MD5: 1a034761685eb58e2b1a345263f64f94 SHA-1: b44a7f92549241169194b49eeac5a3318db8675a SHA-256: 79d47fc40b5314b0555e9006ae6d0d0cacdfb7e9417823c74171310b89c36d17
290 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that exploits CVE-2009-4324 using the media.newPlayer API. The JavaScript is heavily obfuscated but appears to construct a URL or command to download and execute a secondary payload. The presence of a polyglot child PDF further suggests a multi-stage attack. The primary technique observed is exploitation for client execution via JavaScript.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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. (identified after JavaScript deobfuscation)
  • 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.
  • Secondary embedded PDF body has suspicious static findings critical POLYGLOT_CHILD_PDF_STATIC_TRIAGE
    A valid PDF body was found at a nonzero offset inside another container and its carved contents matched PDF exploit or lure heuristics. This catches polyglots where the top-level magic routes to ZIP/OLE while a PDF reader or downstream parser opens the hidden PDF payload.
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • Suspicious extracted artifact medium 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.
  • 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.
  • 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/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/pdfx/1.3/

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0021_000.js
53d4b010cf2e1877fb92814ba7df68c6f821c1000ec778d9f959ac0e49b5a58d		 pdf-javascript-stream PDF /JS object 21 at offset 0x514 2371 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 2 long base64-like blob(s). Carved artifact contains 1 long hex-escaped blob(s).
legacy_pdfkit_stage_000.js
42c3f4df375ff6f58ff655cc4f88b5cc28f0dd33b978390db3538684a6219b74		 deobfuscated-js string-concatenation normalized Acrobat API aliases at offset 0x514 126 bytes
polyglot_child_pdf_off00008f12.pdf
48751ba7a50295afc047bec1ef7f203830ce2999465af2438dda5dfbc7cbbea8		 polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x8F12 121907 bytes
polyglot_child_pdf_off00025358.pdf
0b1c923c8a0028794f3a3244dc498786746334f394e41678cc58ffbeb707d0a8		 polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x25358 6125 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.