More information:
The fonts are referenced in the file style.css of my theme (WooThemes Canvas). The corresponding section looks like this:
@font-face {
font-family: 'Social';
font-weight: normal;
font-style: normal;
src: url('includes/fonts/social.eot');
src: url('includes/fonts/social.eot?#iefix') format('embedded-opentype'), url('includes/fonts/social.woff') format('woff'), url('includes/fonts/social.ttf') format('truetype'), url('includes/fonts/social.svg#woo-social') format('svg');
}