SucKit isn't really an attack, but more of a tool to hide the fact that the system has been compromised and to hide the activities of the intruder from the system administrator. SucKit and other related tools are collectively known as rootkits. You can find out more general info on rootkits here:
and the original phrack article is probably the best place for sucKit specific info:
Keep in mind that although finding a rootkit installed on your system is extremely bad and usually requires a re-installation, it's really a secondary issue in my opinion. A rootkit is simply a cracking tool that has to be downloaded and installed just like other software, which means that someone has to have attacked your system and exploited some other vulnerability on the system (sucKit doesn't have it's own attack mechanism). So when re-building your Redhat system, remember to keep up with security updates, turn off vulnerable applications, use good passwords, use encrypted protocols rather than un-encrypted ones, get a good firewall script, and use good security practices in general. Preventing the attack in the first place is the best line of defense in defeating rootkits. A great place to learning about general system hardening is in unSpawn's security references thread at the top of the forum. There's also some more rootkit reading available there.