Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8cf7fba7619bd7d…

MALICIOUS

PDF

15.7 KB
MD5: ba3f14f37a71d7b56488da59e5b47ed3 SHA-1: e099c1af8c298967b74b21f879233c955b94ae83 SHA-256: d8cf7fba7619bd7dd400211cf32c7863588528082847752c01ddf30678ebf14b
166 Risk Score

Malware Insights

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

This PDF file contains heavily obfuscated JavaScript, including multiple eval() calls and large comment-padded stagers. ClamAV identified it as 'Pdf.Exploit.Agent-36086', indicating a known exploit. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are indicative of a stager designed to download and execute further malicious content.

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
a88fa73f4a81472a9579ca6e1d6e27dcbb9886b7e4ba4528de986fbdbc862924
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425402 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
245aa11648a5094404360f10a0b7086a6f8c6b363821233a61087daa8ed5970d
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 587 long base64-like blob(s).