# installing rkhunter
apt update && apt install rkhunter

# updating its data file of stored values with the current values
rkhunter --propupd

# running a full system check
rkhunter --check # => /var/log/rkhunter.log
rkhunter --check --report-warnings-only


# installing chkrootkit
apt install chkrootkit

# running a scan
chkrootkit
chkrootkit -q