the package chkrootkit is easily installed for fedora (from the repo) with sudo dnf install chkrootkit and is easily run using sudo.
The other seems to use clamav as a backend, but does not show any installation instructions except the install.sh script and that requires a knowledge of shell scripting to understand the install logic.
It seems easy enough to use git to clone the source and then install LMD.
As always, user vigilance and best security practices are key to avoiding malware. Tools to assist are an excellent start, but only are able to detect problems once identified and added into the database used.
Users can protect against and identify known malware IF they keep the tools fully updated and used. New malware is only avoided by user security practices.