Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a8d0f0ce59630c2…

MALICIOUS

PDF

11.5 KB
MD5: 8724c87341d7e5706de7eeeaaba41888 SHA-1: c5746a6a1f8107397d7ec792609d047cdebdcd06 SHA-256: 9a8d0f0ce59630c2f580d45ddee03500cbf150b1a031f12161bccd725b7c3fb2
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.001 Malicious Link/URL T1071.001 Web Protocols

The PDF file contains embedded JavaScript, specifically triggered by the 'Collab.collectEmailInfo' method, which is indicative of the CVE-2007-5659 exploit. The JavaScript is heavily obfuscated using hex encoding and String.fromCharCode, but analysis reveals it's designed to decode and execute a secondary stage payload. This payload is likely responsible for further malicious actions, such as downloading additional malware or establishing command and control. The presence of multiple JavaScript streams and the specific exploit technique strongly suggest malicious intent.

Heuristics 7

  • 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)
  • ClamAV: Pdf.Exploit.Agent-36088 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36088
  • Annotation subject callee-key hex JavaScript stager high PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER
    PDF JavaScript uses syncAnnotScan()/getAnnots() to read an indirect annotation /Subject stream, percent-decodes it through marker replacement, then uses a callee.toString()-derived key to decode and eval the final exploit stage.
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • Suspicious extracted artifact info 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
9fd87306e37a04c361ea1b68a1cf4474b7a018e2270929a8c382cd129d8fc406
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 566 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
annotation_subject_callee_hex_stage_000.js
a8d8fd9265abf0c4a471d516dd0a94a96a8aff2e452d1bb9f0e0a1a7d477df35
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5108 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).