How to list all past remote login information Instead of using "Remote Desktop" for connecting to SQL Server, I and my co-workers are using SQL Server Management Studio to apply changes to the remote server (each user has their own credentials). 

One of us made some changes on SQL tables that put all the data at risk. I'm pretty sure one of us is guilty. My question is this. How can I prove this? Is there any sort of query to show all past remote connections from a client to a remote SQL Server instance? Maybe with IP addresses, computer names, credentials.

Does SQL Server Management Studio have some sort of log file or any query to show remote server logins?

P.S. No full backup on remote the SQL Server instance. Logs are pretty clean.

This is how we login to SQL Server:
You can login with (IP,Port Number) to remote server.By default the SQL Server don't log the logins.

If you have pretty clean logs then you shall not get login history data.
if you have configure SQL Login Audit before pretty clean log. Then some point of time there will be changes that to get the 'SQL Login Audit' details through TSQL like

EXEC xp_readerrorlog; 


It will give only that 'SQL login audit details' which you had configure SSMS. like

1) Failed logins only
2)Successful logins only
3)Both Failed and successful logins


As per MSDN BOL https://msdn.microsoft.com/en-us/library/ms176013.aspx For remote server login details of current user you can find out from TSQL.

SELECT login_name ,COUNT(session_id) AS session_count 
FROM sys.dm_exec_sessions 
GROUP BY login_name;


for ref https://www.mssqltips.com/sqlservertip/1735/auditing-failed-logins-in-sql-server/ and https://msdn.microsoft.com/en-us/library/cc280728.aspx