[Wassup Stats] What are these visits? Who are they?

Since I started running my blog, and starting giving it sometime by writing.

I noticed the number of visits have increased significantly.

But I’m little worried!

When I go to (Wassup Stats), most visitors (say 60%) are something like this:

04:45:45 pm – 178.61.159.93 – /wp-login.php
Referrer: From your blog

What is this? What are they doing on (wp-login.php) page, even though I do not use it nor enabled it for visitors?

Thanks