I have installed the chkrootkit package with sudo apt-get install chkrootkit. When going to the /etc/chkrootkit.conf config file I see the following options:

RUN_DAILY="false"

RUN_DAILY_OPTS="-q"

DIFF_MODE="false"

I assume that the RUN_DAILY option if enabled would get chkrootkit to run an automated scan daily, and that the RUN_DAILY_OPTS sets what kind of scan the daily scan is in terms of which option it is using. Am I correct here? And if so then these automated scans, where are the results logged and how often do these scans occur?

Also, what does the DIFF_MODE option do? And should I enable it?

I have read the README file here and found nothing to do with this config file.