What are these entries that chkrootkit shows???

I ran this command and came across some "interesting" entries. I haven't seen any abnormal activity or logs that would make me suspicious my box is hacked but this is sort of disconcerting. Any idea what these entries are and why knoppix has this stuff installed? I don't like the sounds of rootkits!

Searching for Anonoying rootkit default files and dirs... nothing found
Searching for ZK rootkit default files and dirs... nothing found
Searching for ShKit rootkit default files and dirs... nothing found
Searching for AjaKit rootkit default files and dirs... nothing found
Searching for zaRwT rootkit default files and dirs... nothing found
Searching for Madalin rootkit default files... nothing found
Searching for Fu rootkit default files... nothing found
Searching for ESRK rootkit default files... nothing found

I'm assuming this means the tool was looking for these rootkits but didn't find any. Just curious since I'm new to this tool.

http://www.chkrootkit.org/#tests
If it didn't find anything then I don't see why you might worry about it.

Thanks for the info Underscore. I jumped the gun a little when I saw the words rootkit even though this tool is supposed to help check for those. Thanks for the link/info.