Malicious PDF — malware analysis report

Static analysis result for SHA-256 58adfa33e777d1c3…

MALICIOUS

PDF

118.6 KB
MD5: 8a81c86cf86baa3cbadb9c0830c95243 SHA-1: 5bc8062f89365099af06e80e1b48d1b5f992b4ae SHA-256: 58adfa33e777d1c378a07cb750b83103a5c88c1d7aba77bed1f69ff9585fd0c2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.002 Spearphishing Attachment

The PDF contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_LARGE_COMMENT_PADDED_EVAL'. The presence of 'PDF_EVAL' and 'PDF_FROMCHARCODE' suggests obfuscated code execution. ClamAV also detected this as 'Pdf.Exploit.Agent-36086'. The extracted artifact 'javascript_obj0006_000.js' is a large JavaScript file, likely containing the main payload or exploit logic. The overall pattern points to a malicious PDF designed to exploit vulnerabilities or deliver further malware.

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
22bfc3d305c49ff418ba53f288f491c430c6de6f447fab2441a4629d5b86346b
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627731 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).