Malicious PDF — malware analysis report

Static analysis result for SHA-256 3e85d2dbf958d417…

MALICIOUS

PDF

11.5 KB
MD5: 366853b23ea7401a6a4067c5bc105edb SHA-1: de0bf1a3bcbd28717af37a87caa46a3ad4d0a714 SHA-256: 3e85d2dbf958d4176577f6bd2239e6da12c21f554341acf65a145aa6c8024706
186 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, specifically identified as a stager for CVE-2007-5659 using the Collab.collectEmailInfo method. The JavaScript is heavily obfuscated but appears to be designed to download and execute a second-stage payload. The presence of multiple JavaScript streams and the critical ClamAV detection further support its malicious nature. The exact payload and delivery mechanism are not fully discernible due to obfuscation, hence the confidence level.

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
db8da7adca06eb038c841c8a1f02c5f16efd7773f558b1e00fbe94b5cd26628c
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5030 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).