Yawn, ignoring the obvious, it's this part that is of real concern and what your missing:
"The rootkit scanners for Linux are few and poor. If you're lucky, you'll know how to use
chkrootkit (but you can use strings and other tools for analysis) and show the strings of
binaries on your installation, but the results are dependent on your capability of deciphering
the output and performing further analysis with various tools or in an environment such as Remnux Linux.
None of these free scanners scan the earlier mentioned areas of your PC, either!
Nor do they detect many of the hundreds of trojans and rootkits easily available on popular
websites and the dark/deep web."
The loss of this site: http://vx.netlux.org/ was a loss to everybody.
A place one could download the latest malware to see what it would do, now we have
malware businesses who might now mention a malware's name but little else.
Very very few people can find much of malware in use now.
Rootkits? I'm sure many are running them now; unless one can have access to sites
like http://vx.netlux.org/ to have even a little chance of finding out or even knowing.
(my pet peevee)
and think of how long you've been playing it.