Bringing back tcp wrappers

[Brian Candler]

On 23/06/2021 17:03, Saint Michael wrote:
> I got hacked in 72 servers this week, they installed Bitcoin miners.

Are you saying this happened through opensshd?

What specifically was the cause: do you allow password authentication 
for example?

You can control this by IP address with "Match" clauses in sshd_config.  
For example:

PasswordAuthentication no

Match Address 10.0.0.0/8,fc00::/7
PasswordAuthentication yes

This will allow passwords only from the 10.0.0.0/8 and fc00::/7 
networks, forcing connections from the Internet to use a proper 
authentication mechanism (e.g. keys)