I am new to rkhunter, which I have been using on Lubuntu 18.04. While it is running, it indicates an itemized scan of rootkits in two waves. First, it states: Performing check of known rootkit files and directories. Then: Performing additional rootkit checks. In both instances, literally every item scanned comes back as [not found]. So it is quite perplexing to find the following in the system checks summary at the bottom:
Rootkit checks...
Rootkits checked : 479
Possible rootkits: 4
What is happening here? Why does the summary indicate four possible rootkits when the itemized scan indicate none?