Malicious PDF — malware analysis report

Static analysis result for SHA-256 d963866d04e5fd36…

MALICIOUS

PDF

118.6 KB
MD5: 4caf3ccc95ec10e0a405407c14839403 SHA-1: 941deb5dab48163228c2a3511fa12d1547f9df35 SHA-256: d963866d04e5fd3686c4a0cb5d7ff59ee2582691d040d2b3570d29b2cb0fcdfc
166 Risk Score

Malware Insights

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

The PDF file exhibits multiple high-severity heuristic firings related to JavaScript execution, including eval() calls and a large comment-padded JavaScript eval stager. ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly indicates malicious intent. The embedded JavaScript, though obfuscated, is designed to execute exploits, likely for downloading and running further malicious code. The presence of a large JavaScript object further supports this. The lack of readable document body text means the rationale is primarily based on the script behavior and heuristic detections.

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
7211a661680764ee141770870439de781eac8431967c80c29c5726ac066b224a
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626479 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).