Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb851e9456ae6b6a…

MALICIOUS

PDF

118.6 KB
MD5: a4f4ef831ea8daa071482b1be0a86176 SHA-1: 2195511f73328cebdb55c2e277601794b84ac957 SHA-256: bb851e9456ae6b6a58e68bad7439a1994552e4447ba09832e7190ef3d6e9c06b
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes eval() and String.fromCharCode, indicating obfuscated code execution. The critical ClamAV detection 'Pdf.Exploit.Agent-36086' and the heuristic 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' strongly suggest this is an exploit attempting to download and execute a secondary payload. The extracted artifact 'javascript_obj0006_000.js' is the likely source of this malicious behavior.

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
a4ad62e09987ef8ec013c7920182c5fe0bdf1e60d2ac6ab204e6a1fb3e50849b
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626932 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).