How to block IPs that cause excessive 404 errors with Fail2ban?
I recommend you start by implementing the built-in apache-noscript filter for fail2ban. To do so, add the following lines to/etc/jail.local`
[apache-noscript]
enabled = true
port = http,https
filter = apache-noscript
logpath = /var/log/apache2/*error.log
maxretry = 3
bantime = 600
tweak the bantime setting to your liking and consider implementing the recidiv filter/jail for repeat offenders.
Note: there is a possible bug with the filter regex