Malicious PDF — malware analysis report

Static analysis result for SHA-256 de50258f410d0743…

MALICIOUS

PDF

3.5 KB Created: 2008-31-20 53:85:00 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: dd05e7a9aca2902c563b0e2808d621e4 SHA-1: 2f1ac94121967cb722016a45012a055d806dc77b SHA-256: de50258f410d074361cf7d694cae82f3ae0a18816f5393d79dee68887dfbe049
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript triggered by the OpenAction, which is a common technique for exploiting PDF reader vulnerabilities. The critical heuristic firing for CVE-2007-5659 indicates the use of a specific exploit targeting the Collab.collectEmailInfo function. The embedded JavaScript, particularly the 'numeric_charcode_stage_000.js' file, is heavily obfuscated using `eval()` and `String.fromCharCode()`, suggesting it's designed to download and execute a secondary payload. The presence of multiple JavaScript streams and obfuscation indicators points towards a malicious downloader.

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)
  • OpenAction trigger high PDF_OPENACTION
    PDF has an /OpenAction — code runs automatically when opened
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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_obj0013_001.js
97a06ad0a2f8c683209d92122e2a7ff797e483e715f202b4102758acb8f42a28
pdf-javascript-stream PDF /JS object 13 at offset 0x3D7 13289 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
numeric_charcode_stage_000.js
3579e1fa32d4eef14dfec269af1bed953ecd41d7df31735aaaaee2142a8ea877
deobfuscated-js numeric char-code string decoded JavaScript at offset 0x445 4032 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).