Given there is a large rise in the number of script kiddies and hackers attempting to gain acces to WP sites, the following URL is useful to decode those bizarre url strings you’ll see in your raw log files or in WordFence (live traffic reports).
EG:
Code:
yourdomain.com/%33%55%75%21%88%11 etc etc etc
If your finding stuff like this, use the link below and select URL and Decode. It spits out decoded url info 
Online XML entity encoder | Coder’s Toolbox
Once you know what they’re targeting or attempting to inject you maybe able to find a way to block it. One less worry is always a positive move!