Ok, I missunderstood. The files with domains and urls are at
You can create a new folder with a name like MyOwnBlacklist and a file domain and/or url in it.
The file and the folder have to be owned by squid
chown -R squid:squid MyOwnBlacklist
Now you have to create the database
4.4.4 Converting a URL Database
ufdbConvertDB converts a whole URL database without the need to call ufdbGenTable for each
URL category. ufdbConvertDB requires one parameter which is the top level directory name where the
URL database resides.
It's a part of reference manual
last you have to create a custom template to add your own category to ufdbGuard.conf
I think that's the way.