Malicious PDF — malware analysis report

Static analysis result for SHA-256 a70d421078bf3179…

MALICIOUS

PDF

15.7 KB
MD5: b79915ed01c45d37d92ad43e0a8e50aa SHA-1: 52e46249a869b1a4410972ebd27469f9ffaf5fb6 SHA-256: a70d421078bf3179ff1ec9db2baf6bd3443695665cc744668a8217148e5736f4
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.007 JavaScript

The PDF file contains multiple JavaScript-related heuristic firings, including a large comment-padded eval stager. ClamAV also detected this file as 'Pdf.Exploit.Agent-36086'. The embedded JavaScript stream, although obfuscated, likely functions as a downloader for a second-stage payload, which is a common technique for initial access and further system compromise.

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
ca4da893fa8a721c034e23a6ad6c03f7cba8c140000acf6b6e788c36b8d37571
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425074 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).