Malicious PDF — malware analysis report

Static analysis result for SHA-256 b369bb1004ce99b5…

MALICIOUS

PDF

12.1 KB
MD5: b8e1811f53562e5b7ab5806411ae233c SHA-1: 8c045ef59d1d8d50d41f4c97441bc3587b36d343 SHA-256: b369bb1004ce99b564bcd2896448a1ca27a231784a268fe5bd531961a69ada61
178 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

The PDF file contains embedded JavaScript, identified by multiple heuristics including PDF_JAVASCRIPT and PDF_JS. A critical heuristic, CVE_2007_5659, specifically indicates the use of the Collab.collectEmailInfo method to launch a JavaScript stager. This stager, found in annotation_subject_callee_hex_stage_000.js, is responsible for decoding and executing further malicious code, likely a second-stage payload. The ClamAV detection further confirms the malicious nature of the file.

Heuristics 6

  • 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-36165 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36165
  • 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.
  • 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
3f254d15363cfc46f758dc79a2cb1074c4072b68aa3f4c80a9bf6696d85176e0
pdf-javascript-stream PDF /JS object 7 at offset 0x1A6 1045 bytes
annotation_subject_callee_hex_stage_000.js
a2e01a3b807e2cf649394fb9deb63fd4a015a249e47464aba446815eaf0e384f
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14F 5216 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).