Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4b94ea4594a497b…

MALICIOUS

PDF

118.7 KB
MD5: cee51c20f30b10cee6d65bfba7a13c73 SHA-1: 71e9ae4f5beb38d4917fc2b1b5f6bb3057c51628 SHA-256: b4b94ea4594a497b8d08cc8cc792eb798a3ba4cc1cfa5ce594b98a0da77cfcf7
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 it's designed to execute malicious code. The presence of `eval()` and `String.fromCharCode` within the JavaScript stream strongly suggests code obfuscation and execution. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The primary attack vector appears to be JavaScript execution within the PDF to deliver a secondary payload.

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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
6a920e7c2935bfad72e28c3c83b3849ff4a28c2e8cfa21e66e448d4d838d33ef
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627851 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).