Removing URL field from Comments – I did it, but it's still there???

Hi All,

I’ve had it with the spam that I get in the comments, and I thought that I was being crafty by removing the URL field from my comments on my WP blogs, but somehow I’m still getting comments with the URL field filled in:

A new comment on the post “Prayer for Back Injury” is waiting for your approval
https://www.givenlife.com/prayer/2010/09/prayer-for-back-injury/

Author : weight (IP: 208.77.10.20 , 208.77.10.20)
E-mail : [email protected]
URL : https://www.dumaem-po-russki.org/forum/member.php?u=27358&tab=aboutme&simple=1
Whois : https://ws.arin.net/cgi-bin/whois.pl?queryinput=208.77.10.20
Comment:
yeah my dad will like this

If you go to the above post, you’ll see that there is no URL field, so my thought is that this must be a spambot that knows the WP comments code. Is there a way[Hack] for me to disable the URL field altogether?

Thanks,
Jonathan