Well, the net I'm connecting to has a similar problem, with the diference they're not a few, but about a thousand per day (a thousand only in my channel)
I don't know if it's the same kind of bots, because you specified the nicks with numbers, and we usually don't have bots with numbers on nicks. There are 2 kind of bots. Both are supposed to belong to the same creator (a turkish guy), and he uses web pages and P2P to infect people with a kind of virus, that runs mirc on their computer (of course, they don't know they are running it), with a script that makes spam, and tries to infect more people with it.
The first kind of bot uses nicks like these, I'll paste the 10 last bots I kicked:
rybkkl, ucfm, dyiwfl, yjqwdu, vtbgcv, ebvl, ekbbgyknd, jgltcrdun, smawrq, svdbfdhed... and so on.
The other ones use more sophisticated nicks, maybe from some net in Turkey, and joins with nicks like:
^^ebru^^, AZEP, Guest11329, SESSIZHAYAT, ^^pc^^kolog^^, Hotel_Ca-liforn, murat_-, ANTALY35M, SoNsUzLuGuN_GoL, AHMET-TURAN-40M...
However, I made a script that detect both kind of bots, and kick them, adding their host to a Hash table of "blacklisted", so when he tries to join with another nick (they use the same host for many connections, I guess they use proxy servers), I don't make any lookup, directly I kick him. Of course, if the nick rejoin in a short period of time (these bots don't use to), the nick probably is a human, so I remove the host from the Hash table.
It's based on REGEXP ($regex), and detects about 98% of them, and fails (human) about 1 every 50 nicks.
If you paste me the whois of some of these bots, I can determine if my addon would help you or not, and I can tell you how it is made, so you can also ban these annoying bots.
See ya
