Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3ff291f9477a4ec…

MALICIOUS

PDF

2.4 KB
MD5: e7395299adf5795fb0a9e1f4d3e96c7f SHA-1: b9ba52c3a3f0c56b6137bf4924c1cd3462b38ca4 SHA-256: d3ff291f9477a4ec8c0e30a505937c2d4c1f277c5021574857e392b510a37aa5
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.001 Malicious Link T1071.001 Web Protocols

The PDF file contains embedded JavaScript that utilizes the CVE-2007-5659 vulnerability (Collab.collectEmailInfo). This JavaScript is obfuscated using eval() and unescape() functions, and further processed with String.fromCharCode. The primary intent appears to be the execution of a second-stage payload, indicated by the presence of deobfuscated JavaScript and the critical heuristic firing for CVE-2007-5659. The limited document body content does not provide further context on the lure.

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)
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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_obj111611_000.js
e7d1232c16a6e584ebcad6ed89ed39659361935894de0b1df6aee2e4fe16ce04
pdf-javascript-stream PDF /JS object 111611 at offset 0x84B 478 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
bbe6cbaa9ed5ee9e770c293e48079b603fc0e5b0dc1bf0a3f164fcbcf339482d
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2634 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).