Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb72f5d523a91ae1…

MALICIOUS

PDF

3.5 KB Created: 2008-07-26 19:43:58 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: c6206ad589636dfb776f2312b0e7cf77 SHA-1: 3b8a7e60b3376924d0d34fc6beea99f6f3c1250e SHA-256: cb72f5d523a91ae19b7e9f3e30c1bc8aaa2d10026ef4f796d70466b485dccac7
126 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes the `eval()` function and `String.fromCharCode()`, indicating obfuscated code execution. A critical heuristic identified the use of `Collab.collectEmailInfo`, which is a known indicator for the CVE-2007-5659 exploit in Adobe Reader. The JavaScript is further obfuscated through multiple layers of Base64 encoding, with a custom decoder present. The primary intent appears to be exploiting this vulnerability to execute arbitrary code.

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)
  • 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_000.js
70516f6763f86d596d7e31bb395e6165249e2b58ab9263dbbbd29430123cc3ec
pdf-javascript-stream PDF /JS object 13 at offset 0x3CE 3454 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 4 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
acroform_b64_00.js
ea13f3a4b3d35a8971f4c2b058f35f236008ca2aedfe50f951470b2523468972
deobfuscated-js PDF AcroForm base64 (decompressed) at offset 0x40B 2223 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).