Malicious PDF — malware analysis report

Static analysis result for SHA-256 11c8fad1f676e3f0…

MALICIOUS

PDF

26.8 KB Created: 2010-05-07 10:11:50 +08:00 Authoring application: Acrobat 编辑器 8.0 (via Adobe Acrobat 8.0)
MD5: f0ffa03e745650489d5c9cfff42036c5 SHA-1: 15c01f302d0cec5587cfc4e69063aff10acb4208 SHA-256: 11c8fad1f676e3f08589b27c4c499f069b6afe11550331d790d048edb2fe4a5b
476 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript T1105 Ingress Tool Transfer

The PDF contains JavaScript that triggers a launch action for cmd.exe, which in turn is used to execute an embedded Windows executable disguised as a PDF file named 'hello.pdf'. This indicates an attempt to deliver and execute a malicious payload, likely via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 12

  • Adobe Reader Launch action command execution critical CVE exact CVE_2010_1240
    PDF uses the Adobe Reader/Acrobat Launch action pattern associated with CVE-2010-1240: cmd.exe is invoked with attacker-controlled parameters, paired with an embedded/exported payload.
  • Launch action critical PDF_LAUNCH
    PDF contains a /Launch action whose target is an executable, URL, or UNC path — can start an external application
  • 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.
  • /Launch action target: cmd.exe critical PDF_LAUNCH_COMMAND
    PDF /Launch action specifies an executable target — references a known-dangerous executable (cmd, PowerShell, etc.).
  • Embedded attachment masquerades: declared document, content is windows-executable critical PDF_EMBEDDED_FILESPEC_CONTENT_MISMATCH
    An /EmbeddedFile attachment's declared filename extension or /Subtype MIME type contradicts the magic bytes of its decompressed content. The attachment is declared as a benign document or image but the bytes are an executable or executable-bearing archive. This is a deliberate deception used to hide droppers in PDF attachments and is a generic indicator of embed-and-drop weaponisation, independent of any specific CVE.
  • ClamAV: Pdf.Tool.Agent-1388586 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Tool.Agent-1388586
  • /Launch action paired with attachment-dropping JS API high PDF_LAUNCH_PLUS_DROPPER_JS
    PDF combines a /Launch action with a JavaScript API call that writes or opens an attached/external resource — the canonical shape of the CVE-2010-1240 /Launch + exportDataObject family. Benign PDFs do not pair these surfaces; the combination indicates a drop-and-execute chain regardless of the specific JS API knobs or /Launch target.
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 1 text block(s), carries a click-outward action, and is only 26 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Chello.pdf
956af1225b7801d20b442c2d15d9cbd7b497f01a99fd2829c0c610ab00719b94
pdf-embedded-file PDF EmbeddedFile object 51 at offset 0x2925 73728 bytes
javascript_obj0052_000.js
8e60260324b2abf58f9fa875e60e71692e72a65bbb513b23ec5e5a6e1be78827
pdf-javascript-stream PDF /JS object 52 at offset 0x65E9 56 bytes