I've seen a lot of steps posted for this, and as far as I can tell not one actually works.
Here's what I have done. Keep in mind this is considering users with roaming profiles and widows 7.
Sign out of Skype
Check these areas: (and looking at date stamps helps)
In skype -> tools -> options -> manage advanced settings -> manage other programs accessing skype remove snkb0pt (user must be logged in, also if you see snkb0pt anywhere you should remove it)
Check msconfig -> startup for rogue files (with name of snkb0pt and/or strings of characters found in the registry) and disable them
It is risky if you don't do the permissions right and could indeed make hackers easier to hack your computer so ask a friend that knows alot about this stuff or just try it!
Having Skype is not an advantage if it comes with malware and requires such draconian steps to "clean" it. I just "upgraded" today and this malware warning comes up. I may just forgo Skype altogether and go with Google.