Malicious PDF — malware analysis report

Static analysis result for SHA-256 246a25fe9a8bd492…

MALICIOUS

PDF

15.7 KB
MD5: a7476b041392ad2ad3e36cd66bb1c754 SHA-1: 94ec2552f0c0a9a75f545dd814f9248e1bc3238a SHA-256: 246a25fe9a8bd49214ab031654ff06605c1ecfd87e52bedf9151980453ad751f
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The 'Large comment-padded JavaScript eval stager' heuristic suggests a deliberate attempt to obfuscate the script's execution. The ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The primary function appears to be the execution of the embedded JavaScript, likely to download and execute a second-stage payload, as evidenced by the extracted artifact 'javascript_obj0006_000.js'.

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
a86d0b07508d8c4f42f96305b95f074d466007871b3d5882341739f57f0099d8
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425279 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).