Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a7b379d8ce150a2…

MALICIOUS

PDF

76.5 KB
MD5: fc265cb51bb43a8f7b387356921c6ed2 SHA-1: d487c556f49bcb55fa8e50d8f951fd1972f8ba0e SHA-256: 7a7b379d8ce150a2751829f7b56a002c8f0016993485f4715a714b9b85c86f77
256 Risk Score

Malware Insights

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

This PDF file contains obfuscated JavaScript that exploits CVE-2007-5659 (Collab.collectEmailInfo) to execute arbitrary code. The JavaScript is further obfuscated using binary-XOR encoding and string concatenation, indicating a deliberate attempt to hide its malicious functionality. The primary goal appears to be the execution of a second-stage payload via the eval() function.

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
31c4820c55ba86e431ff43cbab0ce67f9c080e73b1c303b90645a71fa21c3a5c
pdf-javascript-stream PDF /JS object 4 at offset 0xC0 78010 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
c46674042da3900a328476fd39ba15c3237d56af905ede043e38b5eeff20ee3a
pdf-javascript-stream PDF /JS object 4 at offset 0xE3 78121 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
262c33d788460423c906c825695129c5735ecb9a4876d5b95e6e05486206ac40
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3D7 1279 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).