Weird wp-login.php page!

I’ve edited my post:

I was able to login to my WP account until today when I cou’d get the correct wp-login.php page. Instead, “PX1” appeared on the page and I couldn’t login.

The URL is: http://www.ruien.uni.cc/wp-login.php?redirect_to=%2Fwp-admin%2F

Please help! It’s urgent!