Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f681e87341d4d1b…

MALICIOUS

PDF

118.6 KB
MD5: a7b815d5282b4865491a1a3e4ce944df SHA-1: 9a10daea14e4c2929d2ec1ceebc3c4ce11655ec5 SHA-256: 8f681e87341d4d1b93bcff11eb9ad767a35f0f628bb192be803b22c0116d7e2e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1566.002 Spearphishing Attachment T1204.002 Malicious File

The PDF contains embedded JavaScript, including a large, comment-padded eval stager. This indicates the script is designed to deobfuscate and execute malicious code. ClamAV detection as 'Pdf.Exploit.Agent-36086' further supports this, suggesting the PDF is intended to exploit vulnerabilities. The primary IOC is the embedded JavaScript file.

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
775503d923e421fb9b80ce20c7d59fafdb7bc866dd94c879c2037e63025c346a
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627656 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).