Malicious PDF — malware analysis report

Static analysis result for SHA-256 2f7819dbad6b24be…

MALICIOUS

PDF

10.9 KB Authoring application: .a
MD5: 18a461b7578eae6206d27be90d6c7e10 SHA-1: ce293b741db9da9fd9fb66f2148c22566d7f9646 SHA-256: 2f7819dbad6b24bed6422222cbb94276f0643a3d7408755e0aa64649c2964ea5
98 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains obfuscated JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_UNESCAPE. The ML classifier also flagged this PDF as malicious with high confidence. The embedded JavaScript file, 'javascript_obj0018_000.js', is likely responsible for downloading and executing a second-stage payload, a common technique for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0018_000.js
d96379dcad1b821ae14f6e1adeec993e0f64887a2ecb0a63cad504098808ab73
pdf-javascript-stream PDF /JS object 18 at offset 0x4BA 163500 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).