Finding failed SSH login attempts on Debian Systems, Ubuntu, Centos

The following tutorial describes how to list all invalid ssh logins.
We will do everything by executing one command!

To view invalid logins in Debian / Ubuntu systems issue the command:

grep "Failed password" /var/log/auth.log

1	grep "Failed password" /var/log/auth.log

In the Centos system

grep "Failed" /var/log/secure

1	grep "Failed" /var/log/secure

We will get the results as in the screenshot.