Malicious PDF — malware analysis report

Static analysis result for SHA-256 e2ae837687e4afa7…

MALICIOUS

PDF

118.5 KB
MD5: bc9a6c698432cc0a574006bfefeb0d73 SHA-1: 713d4e385ba57ca2938e552f401c382a668a293f SHA-256: e2ae837687e4afa71e0e71f182188b8c1c43cf642a0b6d93bcfa2aec0ab8f480
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.007 JavaScript

The PDF contains embedded JavaScript, with high-confidence heuristics indicating the use of eval() and a large comment-padded eval stager. ClamAV also detected this as Pdf.Exploit.Agent-36086. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are heavily obfuscated but the presence of eval() and fromCharCode suggests dynamic code execution, likely to download and execute a secondary payload. The document body was truncated and unreadable, providing no direct clues to the lure.

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
71ea1bc7a54112d3d48d37dd3383fa8dce1bda65fa5e16fb57ce3d49d0cad37f
pdf-javascript-stream PDF /JS object 6 at offset 0x143 625982 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).
legacy_pdfkit_stage_000.js
cd27e6b571c69ccb3f96b4b0a697a7a7d61addb9248437d8854a22afc0637b71
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 636 long base64-like blob(s).