Is there a way to lock login process for account after 5 unsuccessful logins? Or maybe slow it down to 20 second gap until another login?
I can see lots of tries to connect to my MS SQL server directly.
You can enable Policy Enforcement via a login's CHECK_POLICY setting (for example - honoring account lockout) for a SQL Login in versions 2005+. Command to change the existing login would be ALTER LOGIN.
The actual policy configurations such as "Account lockout threshold" & "Account lockout duration" are part of the Group Policy and set in Windows (local system or at the domain scope).