Question about failed login redirection

Hi! I’ve noticed some failed login attempts in my WordPress logs with a redirect to another domain entirely.

So, instead of a redirect entry like this:

Login Redirect: http://www.mydomain.com/blog/wp-admin/
User Agent: {blah}

I see entries like this:

Login Redirect: http://[removed]/wp-admin/
User Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)

Is this a hacker or script trying to exploit some vulnerability of some kind?

Thanks!