Malicious PDF — malware analysis report

Static analysis result for SHA-256 fcfea8f4e82d2e45…

MALICIOUS

PDF

15.7 KB
MD5: 95f96f59f7627e8710df33ba6e61c8c6 SHA-1: 3debbd319c448ddedbe004a7458d61575fc6a096 SHA-256: fcfea8f4e82d2e4567fefacb529504b87be93c1108ddc22da1d8b86f92f4cbf8
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, including a heavily obfuscated 'eval' stager within a large comment. This stager is designed to decode and execute arbitrary JavaScript code. The ClamAV signature 'Pdf.Exploit.Agent-36086' strongly suggests this is a known exploit. The primary attack pattern involves leveraging this JavaScript to download and execute a secondary payload, typical of many PDF-based malware delivery mechanisms. No specific family could be identified due to the generic nature of the exploit.

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
66c51301084e6d9b73d184934a33df2532fc61530034da3bc4e639d51a555899
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425812 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).