Malicious PDF — malware analysis report

Static analysis result for SHA-256 483994c72be25964…

MALICIOUS

PDF

2.1 KB
MD5: 1717a8968a9a65913f755b01e4a87e42 SHA-1: 1721776fac149407b7db9ead97bbf0c290d56ad8 SHA-256: 483994c72be259646fb985777dee7cfe988a2674914d76b95c3c384f4c5b2b48
106 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1027 Obfuscated Files or Information

This PDF file contains embedded JavaScript that utilizes `eval()` and `unescape()` functions, indicating obfuscated code execution. The presence of `String.fromCharCode` further suggests dynamic code generation. While no specific URLs were extracted, the embedded JavaScript file `javascript_obj111611_000.js` is highly suspicious and likely responsible for downloading and executing a second-stage payload. The obfuscation techniques and the use of JavaScript within a PDF are common for initial access and payload delivery.

Heuristics 6

  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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_obj111611_000.js
9864171cc4152f5d3e5671809dd40cebe1cf9319d0b8bfb0abd003cff50482db
pdf-javascript-stream PDF /JS object 111611 at offset 0x741 332 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).