@yura@udongein.xyz
I assume you are talking about the notorious "Username is not in the sudoers file. This incident will be reported." ?
I know where to find them. All systems I (here and there) adminstrate do not have a need for that though.
@yura@udongein.xyz You log in via SSH? And you have a notification that tells you "you have new mail"?
And in that mail it says something about someone trying to get sudo but failing because they are not sudo?
My first question would be who that particular user is and what they tried to run 🤔
@yura@udongein.xyz The most obvious case would be: You typed it in wrongly ~10 minutes ago.
I assume you did not do that?
Assuming yes:
Next question would be who that user is. I assume the user is the one you use?
If both are true: Someone else is using your account.