Malicious PDF — malware analysis report

Static analysis result for SHA-256 b04aa7f6b16f2dd1…

MALICIOUS

PDF

11.8 KB
MD5: af8dc218f0d4c6a3d2c4815db6799aac SHA-1: 58dcb7660d7efeddc3595e5c69a384b7d8040e9d SHA-256: b04aa7f6b16f2dd19216e91a4c112f98ecb50a81ac4aeaa582e64cb8d7ab9d2e
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious Link/URL

The PDF file contains embedded JavaScript, specifically identified as a stager utilizing the CVE-2007-5659 vulnerability (Collab.collectEmailInfo). This script is heavily obfuscated using hex encoding and string concatenation, indicating an attempt to evade detection. The primary function of the script is to decode and execute a secondary payload, likely for malicious purposes such as downloading further malware or establishing a backdoor. The ClamAV detection further confirms the malicious nature of the file.

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
f475f2ed6c2c51d540d2d745d9b91f07c462e7649be4d3080e349e85b7fe43b1
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5188 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).