Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3eb70d08d398df6…

MALICIOUS

PDF

413.9 KB Created: 2008-04-23 16:42:36 +08:00 Authoring application: Acrobat PDFMaker 6.0 for Word (via Acrobat Distiller 6.0 (Windows))
MD5: 4923ca3b5e97d70263561a05cd1c85e3 SHA-1: 5792c5c321e914970af56f78334643c544fb64f2 SHA-256: b3eb70d08d398df6ea9fa7c399b23ca5d4cb129b5d9a6fa640dd19346b24eff5
342 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1027 Obfuscated Files or Information T1140 Deobfuscate/Decode Files or Information T1105 Ingress Tool Transfer

The PDF contains embedded JavaScript that utilizes eval() and unescape() functions, indicative of obfuscation. This script is designed to exploit CVE-2007-5659 (Collab.collectEmailInfo) and ultimately drops an embedded Windows executable payload (ctfmon.exe). A secondary embedded PDF was also found with similar suspicious findings. The primary attack vector is the exploitation of a PDF vulnerability to deliver a PE payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 11

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • Embedded Windows executable payload in PDF stream critical PDF_EMBEDDED_PE_PAYLOAD
    PDF stream bytes contain an embedded Windows executable with a verified PE header. Exploit chains often hide droppers inside ordinary streams rather than standard /EmbeddedFile attachments.
  • 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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (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.
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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/xhtml
    • http://www.xfa.org/schema/xfa-data/1.0/
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/iX/1.0/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/pdfx/1.3/
    • http://ns.adobe.com/photoshop/1.0/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://purl.org/dc/elements/1.1/

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
ctfmon.exe
08a4f2446b9756ff03d232dd278508e29f82ab40e06c828c9dc92b8137785ee8		 pdf-embedded-file PDF EmbeddedFile object 29 at offset 0x11B1 13253 bytes
javascript_obj0026_000.js
97607f052bdaa41ec51cbb9f3d6c0ecdda7860b008e351c9c36e052afa13967d		 pdf-javascript-stream PDF /JS object 26 at offset 0xA98 10231 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long hex-escaped blob(s).
polyglot_child_pdf_off000621fd.pdf
e418dbe843a9a2ddc96a0a153d3563ccaadefb2ab330ca92426a3d9bb1415ff5		 polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x621FD 21933 bytes

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