Germany’s Federal Office for Information Security (BSI) warns that cybercriminals have compromised around 16 million email addresses of online accounts. BSI launched a service to help users find out if their credentials have been stolen: https://www.sicherheitstest.bsi.de/ (in German)
After you submit, you see in a second window a code which is going to be present in the email that you might receive. If your email address is not present in the list of BSI, you will not receive any email.
No matter whether you understand German or not, all you need to do is to check the box on the top left corner, add your email in the field and then click on the blue button.
According to BSI, researchers and law enforcement agencies have determined that 16 million usernames (usually email addresses) and passwords have been compromised after analyzing botnets.
We know that many users use the same login information for multiple online services, despite the fact that we continuously warn that this is not a good practice. If you do this, then the first thing is to check if your email has been compromised using the above site. No matter if you get any results back or not, you should change the password for each service according to the advice we wrote here.
Avira is involved in the BSI initiative by providing the free second opinion scanner PC Cleaner.
If you wonder what does this have to do with the email address: the credentials were stolen by malware installed on the PC. This tool does nothing else than scan your computer and search for malware (any kind of malware, not only that responsible for stealing credentials).