Malicious PDF — malware analysis report

Static analysis result for SHA-256 444f2a706f19d674…

MALICIOUS

PDF

118.6 KB
MD5: 13be1352ba4cbeb9232eaa71210e9c0a SHA-1: 5fabfe3ca4b4863a9aceb4a033d3dc1bf49a604c SHA-256: 444f2a706f19d674d8a5acbd6cee7f94a86cfee5e018d7d7eda0fc9cbf2a8b04
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment T1071.001 Web Protocols

The PDF file contains embedded JavaScript that utilizes `eval()` and `String.fromCharCode()`, indicating an attempt to obfuscate malicious code. The heuristic 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' strongly suggests a stager designed to download and execute a secondary payload. While the specific payload and download URL are not directly visible due to obfuscation, the presence of these indicators and the ClamAV detection ('Pdf.Exploit.Agent-36086') point to a common PDF exploit delivery mechanism.

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
622843730eb5700e656ddd775b2ce216f3dccd50a9cb798125c04bda3f6c97c9
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627089 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).