I.P. Deny listings?

A quick look at my webhost logs shows a bunch of ip sniffing attempts from a range in China and Japan. I managed to block those ranges but I'm curious. Is there a listing anywhere of known hacker I.P. address ranges that I could just add to my host deny manager?

You can certainly buy IP blacklists which will save you a lot of time; and if you dig around you can find quite a lot of lists for free (Especially on support boards for software like phpBB or vB)as many webmasters just build a list as they go.

Sadly the easiest way is still to block China, Japan and Russia if you're not focussed on a global market. If your webhost has a support team I'd definitely talk to them as they'll have a good bit of knowledge on the area (Y)

I definitely wouldn't block entire countries. There are good anti-spam services around which maintain up-to-date lists of known spammer IPs. Or you may be able to just ignore it if it's not causing a specific problem - every website faces this problem.