Malicious PDF — malware analysis report

Static analysis result for SHA-256 329939f3ae1838b3…

MALICIOUS

PDF

43.5 KB Created: 2009-12-16 23:15:23 +08:00 Authoring application: Acrobat 编辑器 8.0 (via Adobe Acrobat 8.1.2)
MD5: 2d11eabe8ab70d57d1203f7e4074c20a SHA-1: 895d7f4cf5a1703abfc3589f578e6830dd6cf7d3 SHA-256: 329939f3ae1838b3d87e579e6e4517b3b4878bced0eeb4472b4225b8bf789e7b
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF contains embedded JavaScript that is obfuscated and utilizes the unescape() function. The critical heuristic firing for CVE-2009-4324 indicates the exploitation of a known vulnerability in Adobe Reader related to the media.newPlayer API. This suggests the script is designed to download and execute a second-stage payload. The presence of a secondary embedded PDF further supports a multi-stage attack.

Heuristics 7

  • 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)
  • 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. (matched inside decoded stream)
  • 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. (matched inside decoded stream)
  • 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/

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off0000063a.js
d786d31840a84cc1a2f19e246e8f2dcee55446ffecf618ef72b216e27f43b272
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x63A 2609 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(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 0x63A 126 bytes
objstm_0023_00.bin
e8bfe65c34a535b0837ce7c541e45b42ab61e1ff13de05788daf7770f9a1ec0e
pdf-objstm-decoded PDF /ObjStm 23 0 obj (inflated) 274 bytes
polyglot_child_pdf_off00007bdf.pdf
d960ead972ce47a236e33801a5b38882d16ac73c5b875fac7dc72b55dd1efc68
polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x7BDF 12790 bytes
polyglot_child_pdf_off000095e8.pdf
0b1c923c8a0028794f3a3244dc498786746334f394e41678cc58ffbeb707d0a8
polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x95E8 6125 bytes