https://debtags.debian.org/search/bytag?wl=security::integrity

fail2ban

debsums

Report changed files (also configuration files)

debsums -a -c
/etc/default/debsums
CRON_CHECK=weekly

debsigs

apt-get install debsigs debsig-verify

debsecan

debsecan is a tool to generate a list of vulnerabilities which affect a particular Debian installation. debsecan runs on the host which is to be checked, and downloads vulnerability information over the Internet. It can send mail to interested parties when new vulnerabilities are discovered or when security updates become available.

tripwire