Malicious PDF — malware analysis report

Static analysis result for SHA-256 cac4f74946919da2…

MALICIOUS

PDF

118.8 KB
MD5: 5cb24bcc8220451f809e25edd448621c SHA-1: b39c4b70473a61ddab2f90ec2ff463031d9eb5a2 SHA-256: cac4f74946919da288d8dd35db8a4bf63de115c3d054fd792c7c2cb1d0a295e5
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript

The PDF contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_JS_LARGE_COMMENT_PADDED_EVAL'. The 'PDF_EVAL' and 'PDF_FROMCHARCODE' firings suggest obfuscation and dynamic code execution within the JavaScript. The 'CLAMAV_DETECTION' for 'Pdf.Exploit.Agent-36086' strongly suggests this is an exploit document. The extracted artifact 'javascript_obj0006_000.js' is likely the stager for the exploit.

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
f3cceb779c8a446bcf6b39ce7afeb3bd4a27949e42ff8a151c9db3bb60fae5c0
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627200 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).