tucok3.php

For over a month now, if have had unwanted searches every 1 or 2 seconds from all over the world
Wordfence IP blocking and country blocking is stopping these attacks
The format is always the same, they are looking for this address
https://www.mydomain.com/tucok3.php?e=80nelq84p0bd
Where the area in bold above changes Examples
https://www.mydomain.com/tucok3.php?e=k5vhu961zf
https://www.mydomain.com/tucok3.php?f=jkjxg56o5s919
https://mydomain.com/tucok3.php?l=0dbtfhwjfx2gt

What are these people looking for?
They are chewing up my bandwidth, how do I dissuade them from these attacks?
Apart from blocking them, do you have any other suggestions as to what I can do?

Thanks

https://www.ads-software.com/plugins/wordfence/