Malicious PDF — malware analysis report

Static analysis result for SHA-256 708109b59701e7fe…

MALICIOUS

PDF

75.9 KB
MD5: ee9255c03a25bcb224b343b7422a9b73 SHA-1: 134131564a24546236a37700ef7df8ba9ad6d14d SHA-256: 708109b59701e7fea973e9e831b5bb9b25c1703f7927d29ad3b000a2befaef07
256 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that exploits CVE-2007-5659 using the Collab.collectEmailInfo method. 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, as suggested by the 'PDF JavaScript exploit cluster' and 'Binary-XOR JavaScript stager' heuristics.

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
4adaae226beed2b165b345294914a767ae05a12ac1249ab2cf27ee4dc8a91f5e
pdf-javascript-stream PDF /JS object 4 at offset 0xC0 77434 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
71bfa2fbf5a966f5628c7ba43fb1c8a1fe3ae366def9634729e62ea1ae92c653
pdf-javascript-stream PDF /JS object 4 at offset 0xE3 77545 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
15fd3aaa4b8bcd957e7d4dd3c6d0ba15018596f709b0920d4e67bd4b19093813
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3D7 1267 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).