Malicious PDF — malware analysis report

Static analysis result for SHA-256 5148f906b52ee0e3…

MALICIOUS

PDF

118.6 KB
MD5: 86d1f4b5cd9a21c7bc5b2948245c865d SHA-1: e12c97a7eb9a7c8a97afa81f787f5f1b726674b3 SHA-256: 5148f906b52ee0e3576cab49dfe59081a8630508cb50ec192ddea55f8a31a3f9
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, including a large comment-padded eval stager, indicating an attempt to obfuscate malicious code execution. The presence of eval() and String.fromCharCode() calls strongly suggests the script is designed to decode and execute a secondary payload. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature, likely involving exploit delivery.

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
5e80f06ccb114333f374926eabb02889f62767dbcc0c59f6430968e551b6a215
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626549 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
2465c72653d571193af9db589d07e01da89084446492eafbe3d7e274b386aa81
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 609 long base64-like blob(s).