Malicious PDF — malware analysis report

Static analysis result for SHA-256 21fd0059ea7e92c8…

MALICIOUS

PDF

118.8 KB
MD5: 2f228d59ddd4381a59f0e9b023b21ba4 SHA-1: 094c6e47ad8a7293b9a8f5ba5b614fa60c3ec43e SHA-256: 21fd0059ea7e92c8b181977a9293fdf764e2b4b4d0159983756d2f103d34c4fd
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains embedded JavaScript, including a large comment-padded eval stager, indicating it's designed to execute malicious code. The ClamAV detection 'Pdf.Exploit.Agent-36086' and the presence of a large JavaScript object further support this. The script likely downloads and executes a second-stage payload, though the exact mechanism is obfuscated.

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
2db285ee4865fc81e84e9bc38bb980547c5ba6d4a76e1fb6ce0d53474a7c486f
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627537 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).