Malicious PDF — malware analysis report

Static analysis result for SHA-256 6aa83b6ffd8e2163…

MALICIOUS

PDF

118.5 KB
MD5: 046f425be2d4a4c6c9218a515a1f3473 SHA-1: 003c2251d7a36dd364d90eb0446cdb6198cbe970 SHA-256: 6aa83b6ffd8e2163761d34e08b9612732702859b06f5f6e17ed4968b77efe651
296 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The PDF file contains heavily obfuscated JavaScript, indicated by multiple heuristics including PDF_EVAL, PDF_FROMCHARCODE, and PDF_JS_LARGE_COMMENT_PADDED_EVAL. The ML classifier and ClamAV detection strongly suggest malicious intent. The JavaScript is designed to execute code, likely downloading and running a secondary payload, which is a common technique for initial compromise via malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • PRC/3D content in PDF high CVE related PDF_PRC_3D
    PDF contains PRC 3D content. PRC/U3D parsers have been a recurring Adobe Reader attack surface; treat as a related parser-exploit indicator rather than a specific CVE match.
  • 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.
  • ClamAV: Pdf.Exploit.Agent-36086 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36086
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Large comment-padded JavaScript eval stager high PDF_JS_LARGE_COMMENT_PADDED_EVAL
    PDF JavaScript contains a very large stream padded with long random-looking block comments around String.fromCharCode and eval. This is an exploit-kit obfuscation shape used to bury a decoder and recovered stage inside noise, not normal PDF form automation.
  • 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_obj0006_000.js
f4a15ee3b92659f2d33f70e6e2701733a189ec95b21b80f493db456bdc4be754
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627327 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 42 long base64-like blob(s).