I have an Amazon EC2 instance and i don't have anything running on it yet but my event log is full of below error
"Login failed for user 'sa'. Reason: An attempt to login using SQL authentication failed. Server is configured for Windows authentication only. [CLIENT: 220.127.116.11]"
What is this ? is someone trying to attack or is it something internal ? I know about the authentication mix mode and etc... just want to make sure what it is before I change the sql security settings.