Malicious PDF — malware analysis report

Static analysis result for SHA-256 760aa8af61e577b9…

MALICIOUS

PDF

118.6 KB
MD5: 440879083137a4d759d49428b9ba7c84 SHA-1: ee8c6999bdda870c36e0afcb968ea49faf367d40 SHA-256: 760aa8af61e577b921894dadfbc3358466f75cf2c52034214264999e40fb78e7
256 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by multiple heuristics, including critical findings for JavaScript exploit clusters and a large comment-padded eval stager. The embedded JavaScript is heavily obfuscated but the presence of eval() and String.fromCharCode() indicates it is designed to download and execute a second-stage payload. The ClamAV detection name 'Pdf.Exploit.Agent-36086' further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • 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
9a44e7141d9b1840b827ef34fbed231ece7212936d6d1edba57afcf5cd697584
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626356 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).
stream_002_off0001d866.bin
4495fcb597da98b5b50415291bf82ddf4a1b999eee56b56a2c6ccf2277aa5c49
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1D866 200 bytes