Malicious PDF — malware analysis report

Static analysis result for SHA-256 1286656cc2d62728…

MALICIOUS

PDF

12.7 KB
MD5: 77e5bcd8503bea54f38f395f11146215 SHA-1: 10d7a51e01b490f262b2094275c693804d0cf850 SHA-256: 1286656cc2d62728084d8c2272cc40f39a591861ab4c2cd76931ef85a124f33e
116 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is heavily obfuscated using character code manipulation. The script appears to be designed to exploit a vulnerability within the PDF viewer, likely to download and execute a secondary payload. The critical heuristic 'PDF_JS_EXPLOIT_CLUSTER' strongly indicates an exploit attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
d2233358777d1aaed8efae57eefbdc7f0ddc83b20eb36c734bc8ee388da7c061
pdf-javascript-stream PDF /JS object 5 at offset 0x107 1418 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).