Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7ecde71b4782512…

MALICIOUS

PDF

15.7 KB
MD5: c04afbc01e91d4d0bcb8c90d3ed87fb5 SHA-1: 89aa7a65e23f7d860242077aea936e6a41336e3c SHA-256: a7ecde71b4782512a9c8ac273d84dbc15b553e4404689c1fb3b0abff1817bd80
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious JavaScript

The file is a PDF containing embedded JavaScript, as indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The critical ClamAV detection of 'Pdf.Exploit.Agent-36086' strongly suggests it's a known exploit. The embedded JavaScript, particularly the 'Large comment-padded JavaScript eval stager', is designed to execute arbitrary code, likely downloading and running a second-stage payload. The document body was unreadable, but the script behavior is clear.

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
98c25a56afc23ec057a536b3aa60af32d9353c3452b80dea444da99e70c2e3fb
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425033 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).