Malicious PDF — malware analysis report

Static analysis result for SHA-256 c836d5ec6efffdfe…

MALICIOUS

PDF

147.0 KB Created: 2010-06-29 10:30:35 +08:00 Authoring application: Writer (via OpenOffice.org 2.2)
MD5: 977bcbe87d9280ef618734037f07f7a1 SHA-1: ee32866da2951a000fbd319b2a0fec593721f523 SHA-256: c836d5ec6efffdfe7fd667ad16cb06d87e2ee7dd8ee5de2b8623b79d799ecc13
244 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious Link T1566.002 Spearphishing Attachment

The PDF sample contains embedded JavaScript and exploits CVE-2009-4324, indicated by the 'media.newPlayer' heuristic. This exploit is used to execute a malicious payload, likely a second-stage downloader, as suggested by the 'PDF_JAVASCRIPT' and 'EXTRACTED_FILE_STATIC_TRIAGE' findings. The presence of multiple embedded PDF objects and the 'POLYGLOT_CHILD_PDF_STATIC_TRIAGE' heuristic further indicate a complex, multi-stage attack. No specific family could be 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
024248d14c75712b034227b73904560bf384941714355c7e25c079e3f8967707
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x392 4264 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_off000221ed.bin
0420f4d0cc553e63ac4e95e62d3543aa4a1e77e4e64b52190ac56fe5e7615512
pdf-font-stream PDF embedded font (sfnt) at offset 0x221ED 4812 bytes
polyglot_child_pdf_off00013e7f.pdf
cc3e98254f38c72f2143b78e6e437f4f7e14e774c17113a8e9ae8ac90c2c1ac6
polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x13E7F 69003 bytes
polyglot_child_pdf_off0002341d.pdf
0b1c923c8a0028794f3a3244dc498786746334f394e41678cc58ffbeb707d0a8
polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x2341D 6125 bytes