Malicious PDF — malware analysis report

Static analysis result for SHA-256 c991b165d56b7f97…

MALICIOUS

PDF

3.6 KB Created: 2008-31-20 53:85:00 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: d6c9d7828e0c3b540d61c9edffe801c7 SHA-1: a1d16d4803790837d1ac4d66bbcb321a98b63f7e SHA-256: c991b165d56b7f97301881b76e32130cb871bd92c73dba9c94dad9c8bf96d9d8
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell 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 CVE-2007-5659 heuristic indicates the use of Collab.collectEmailInfo with a numeric character-code string to decode and evaluate JavaScript. This JavaScript is likely designed to download and execute a second-stage payload, as suggested by the presence of obfuscated JavaScript streams and the overall malicious verdict.

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
0c8a1aa2b5c31ae6de7d62323ca6bb5f44a54fa934d045e126ca9c7a91ff33a3
pdf-javascript-stream PDF /JS object 13 at offset 0x3D7 14227 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
e273c5ee534706787cc28c11658ecd6da7d9cb5e8076bed7b3485fb8c917d859
deobfuscated-js numeric char-code string decoded JavaScript at offset 0x445 4260 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).