Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1a75f1e6492a9b4…

MALICIOUS

PDF

118.7 KB
MD5: aba516394fd5b02ebd924a475c7e7168 SHA-1: e1ad53957813402c6097d9df3cb5bfea35465303 SHA-256: f1a75f1e6492a9b41cea3f68e36326633c337f01f869270e794e3341811a64ef
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains embedded JavaScript with multiple heuristic firings indicating obfuscation and eval() calls, including a large comment-padded eval stager. ClamAV detected this as 'Pdf.Exploit.Agent-36086', strongly suggesting it's a known exploit delivery mechanism. The presence of JavaScript actions and streams points to the script being responsible for the malicious behavior, likely downloading and executing a second-stage payload.

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
e2e6048b2a2adce17ec368902d0f0dc920589a9fa6909fa41a65165a3788665d
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627402 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).