How to change class to footer icons

[italyhitech]

Hello everyone, I would like to ask how can I change the class of the footer icons. I tried pressing F12, and through console I saw that those icons have the "_blank" class.
That's the code that I'm seeing right now: "<li class="facebook"> <a class="_blank" href="https://www.facebook...171440662896547" target="_blank"> <span>Facebook</span> </a></li>" Now, "_blank" class is getting showed. Why there's no class?
I tried to create a rule named "_blank" in the "global.css" file to solve this problem, but this is not what I wanted to do at all... I would like to change the name of that class, I also checked ".tpl" files but I didn't find anything useful. Should I add something to the "global.css" file?

#social_block li a {
             display: block;
             width: 25px;
             height: 25px;
             background-position: center center;
             background-repeat: no-repeat;
             }
              #social_block li.facebook a{
                background: url(../img/facebook.png);


Thank you everyone.