Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ba3b23767d5e550…

MALICIOUS

PDF

118.5 KB
MD5: 96dd3dc8240c30171822403b89ea53b2 SHA-1: 65da7a8b9f24c5add0d5fa5792ac58b2474808a1 SHA-256: 9ba3b23767d5e55072c66ed13fab16632e47ec103276047ce8f334d592d74f0e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.002 Spearphishing Attachment

The PDF file contains embedded JavaScript, including a large comment-padded eval stager. This indicates the file is designed to exploit vulnerabilities within PDF readers. The presence of `eval()` and `String.fromCharCode` suggests obfuscated code execution. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature, likely involving the download and execution of a secondary 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
39353c32102db059b17427748dfed2aca4915dc5ef28b2802b42abbb79ec6ff4
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627257 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).