Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f7d28c47e8c8875…

MALICIOUS

PDF

15.7 KB
MD5: 87649f20f6fdca662d598ef79ac99ee9 SHA-1: 5d67ff84f00c026c5759d8bfff6472c8616ef3a6 SHA-256: 9f7d28c47e8c88756a9af3f30629c756965ee50d77731b6f2035f0b908c87dd4
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious JavaScript

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_EVAL'. A critical ClamAV detection of 'Pdf.Exploit.Agent-36086' strongly suggests a known exploit. The presence of 'eval()' and 'String.fromCharCode' within the JavaScript stream points to obfuscation and dynamic code execution, typical for downloading and executing further malicious content. The large, obfuscated JavaScript stream further supports this. The document body was unreadable, so the rationale is based solely on the script and exploit indicators.

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
ffe392f7cfe9ada075f6bc894f88308037cd1892d8d08be7b9b5a2db3083b1e9
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425771 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).