Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2e64590ab4310ff…

MALICIOUS

PDF

118.6 KB
MD5: 2705fd6b99929197eaeee4cc3f419b2f SHA-1: b1d70987cbddc8d50e68d2808056aa27fe198fbd SHA-256: b2e64590ab4310ff81db63771c56fb20b6ffe064a5c5d26cd1281db4399df4c4
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, including a high-severity heuristic for a 'Large comment-padded JavaScript eval stager'. This indicates the script is designed to obfuscate and execute malicious code. The ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The primary attack pattern is likely initial access via a malicious PDF attachment, exploiting vulnerabilities through the embedded JavaScript.

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
01c166a895ae5307a358ee1ab757d8f3996e5f72ab3d08220bbf72b6362b9c98
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626486 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).