www.gametracker.com usually bans this servers, but I couldn't found their list.
Where's some (you can try by yourself, some add itself to your favorites):
unreal://209.160.77.22:5555
unreal://209.160.77.22:7777
unreal://209.160.77.22:7866
unreal://209.160.77.22:8888
block entire 209.160.77.22 should be the best.
unreal://8.9.8.142:7777
--------Another weird servers--------
unreal://72.5.152.96:7777 (this one seems doesn't have directly fake bots, but you get in there redirected by unreal://209.160.77.22:7777 and then it adds itself directly to your favorites without permission after visiting 209.160.77.22)
unreal://72.5.152.225:7777(it adds itself directly to your favorites without permission after visiting 209.160.77.22)
unreal://72.5.152.229:7777(it adds itself directly to your favorites without permission after visiting 209.160.77.22)
unreal://72.5.152.96:7777(it adds itself directly to your favorites without permission after visiting 209.160.77.22)
unreal://72.5.152.193:7777(it adds itself directly to your favorites without permission after visiting 209.160.77.22)