Getting 403 Bad Behavior errors

Since I’ve updated to latest WordPress, seems like I’m getting this error upon login attempts to my site. I have never seen this before so I’m just guessing at where the issue is coming from.

Here is the error:

Error 403

We’re sorry, but our system has detected your usage as potentially malicious. You will not be able to access /login/ on this server.

This message may provide more information: You do not have permission to access this server. Before trying again, close your browser, run anti-virus and anti-spyware software and remove any viruses and spyware from your computer.

If you are a legitimate user, this code will allow you to get help: xxxxxxxxxxxxxx

You may be able to fix this yourself using the above code. Please click here for more information.

If you are unable to fix the problem yourself, please contact your webhost (or this site’s administrator if you are not the owner) and be sure to provide the code shown above.

Thanks for your help!

https://wordpress.org/plugins/theme-my-login/