Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1caaeac6652edcd…

MALICIOUS

PDF

194.6 KB Created: 2010-06-29 10:30:35 +08:00 Authoring application: Acrobat 编辑器 8.0 (via Adobe Acrobat 8.0)
MD5: 8111cffb242c84863dd5518119437e08 SHA-1: b6ce8cf212015445135da1092b0d0018657678ed SHA-256: a1caaeac6652edcdb2572919fc9ca086b70f93f20e8cc9dc641fd857ae26ccbc
244 Risk Score

Malware Insights

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

This PDF file exploits CVE-2009-4324, a vulnerability in Adobe Reader related to media player handling. The exploit appears to be designed to download and execute a secondary payload, as indicated by the embedded JavaScript and a secondary PDF file. The presence of obfuscated JavaScript and a secondary PDF suggests a multi-stage attack. The specific exploit trigger, 'media.newPlayer', is directly identified.

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)
  • 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.
  • RichMedia (Flash) high PDF_RICHMEDIA
    PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector (matched inside decoded stream)
  • 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 file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload (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 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off00000392.bin
33ead50df8492f93c377e6cbbe953a31f60bb3c915b280d9020d2b7ab73686bb
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x392 4147 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 3 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 0x392 126 bytes
objstm_0017_00.bin
dd7918c182d6e2b8d996a6b8ee81663c49a0cb297efe1e1fa3c5af0c987bde84
pdf-objstm-decoded PDF /ObjStm 17 0 obj (inflated) 871 bytes
font_00_sfnt_off00021a83.bin
4a227a793c9e23c64ca306164d5abbfab63bfc0c00cf9286e25d1ef5d01cb210
pdf-font-stream PDF embedded font (sfnt) at offset 0x21A83 183480 bytes
polyglot_child_pdf_off0002088f.pdf
59ac775fd39f7eb1e692a290ace92b5dae75e784b6497d1667e891a317fdb0bd
polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x2088F 65980 bytes
polyglot_child_pdf_off0002f25e.pdf
0b1c923c8a0028794f3a3244dc498786746334f394e41678cc58ffbeb707d0a8
polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x2F25E 6125 bytes