Before you use that Linux VM you got from that cheap #hosting provider, a sample of things you might want to check:

* unexpected daemons
* unexpected network listeners
* unexpected user accounts
* SSH keys in /root/.ssh
* lsblk for unprovisioned disk(s)
* undesirable /etc/resolv.conf
* ufw/iptables setup
* shell history (yes, on new installs)
* unexpected cron jobs/scripts

and I'll go into more detail on one hosting provider's unusual SSH server setup soon. I probably haven't seen it all, but I've seen a lot.