Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d6a2f44daf8f67d…

MALICIOUS

PDF

118.7 KB
MD5: eb57289579ec4d3d54e78885963e024b SHA-1: 5ae4e22b77d0051d71f60e789570130cc705e4d1 SHA-256: 3d6a2f44daf8f67d632cde220c2474aed905431838f3860cceb9cfb4c27deaa9
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious JavaScript

The PDF contains embedded JavaScript, including a large comment-padded eval stager, which is a common technique for obfuscating malicious code. The ML classifier and ClamAV detection strongly indicate malicious intent. The primary function appears to be the execution of JavaScript, likely to download and execute a second-stage payload, as suggested by the 'Pdf.Exploit.Agent-36086' ClamAV signature.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • 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
3a473f8c0d5ed6fa5f0516ce591f53ed196d46282e216db29a008df35a40ed3b
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626841 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).