Malicious PDF — malware analysis report

Static analysis result for SHA-256 2cad4aa0f1b31506…

MALICIOUS

PDF

118.5 KB
MD5: d354fd9725c316f85be10e01e42af30d SHA-1: 646e7b0b929c6a16a179fb7304d5f5bbba479355 SHA-256: 2cad4aa0f1b31506629de7e2684d863ee39e2ffde0113448e1777f9dc94eadc3
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, including a large, comment-padded eval stager. This JavaScript is heavily obfuscated and uses String.fromCharCode, indicating an attempt to hide malicious code. The presence of these elements, along with ClamAV detecting it as 'Pdf.Exploit.Agent-36086', strongly suggests the PDF is designed to exploit vulnerabilities or download a second-stage payload.

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
f3dd5269bf3724c46f1a8a6331dd78b2058497359083cf9f489c50a6b344d3e1
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626796 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).