Malicious PDF — malware analysis report

Static analysis result for SHA-256 046779612382e59d…

MALICIOUS

PDF

74.7 KB
MD5: ce5ba417c9491796f150c49d3bf99bc2 SHA-1: 4e552cd2f695faabb98f24957811aa47c3e0b7ca SHA-256: 046779612382e59d0c5cdeff9d1865daa4d7dd4908fe6bd3c40bb2540935aaff
256 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains JavaScript that exploits CVE-2007-5659 by calling `Collab.collectEmailInfo`. The JavaScript is heavily obfuscated using binary-XOR encoding and string concatenation, but analysis indicates it's designed to download and execute a second-stage payload. The ML classifier strongly flags this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • 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)
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution
  • Binary-XOR JavaScript stager high PDF_BINARY_XOR_JS_STAGER
    PDF JavaScript stores viewer-version payload branches as long binary digit strings, XORs each bit pair, converts 8-bit chunks with String.fromCharCode, and evals the recovered 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.
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0004_000.js
a045b39f07b8bbf70d5a2773c3484fc76b205fa7ac75ac9c2ec7c07272f861a3
pdf-javascript-stream PDF /JS object 4 at offset 0xC0 76181 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).
javascript_obj0004_001.js
0d8eef9c28d89842c06b8373d2b4810a508d609464071ca9d70643008b28857f
pdf-javascript-stream PDF /JS object 4 at offset 0xE3 76292 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).
binary_xor_stage_000.js
0d891a651370ca5b4f48a97d6ef2de6e0224aa6b9569968b2141a55f9a0b862c
deobfuscated-js binary-XOR decoded JavaScript at offset 0x65AE 1237 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).