Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e38b386d2be1198…

MALICIOUS

PDF

118.5 KB
MD5: 0bdc36ac106ee825741e3505233c3f97 SHA-1: 639cd4da5ea5b22b139da2db56912375c1e44577 SHA-256: 8e38b386d2be119853f06d6f23dc97fc075186a355c49f74f2a35cb7bf78a9ed
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, with high-confidence heuristics indicating the use of eval() and a large comment-padded eval stager. ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly suggests exploitation of a PDF vulnerability. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, which is a common technique for initial access.

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
f30f67ea39feb1e4ebf43d63a03b5ae9b96a2a9078c4f58615ad16dc5ee51904
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627333 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
d2f0adf696bec0168f9901d18cb0b5a9685751af3c6d8e6c6796e1df94ae584c
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262116 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 570 long base64-like blob(s).