There are two types of footprints related to wordpress, both outside the wordpress core.
1.
Footer: Almost all WordPress themes come with a footer credit - something like theme by abc designer or company. it easy change the default so called foot print by editing footer.php, if yo're using free theme or download premium theme for free, it is wise to check footer for exploits, one of key reason to get hacked WordPress websites is, footer exploit. To delete the so called Footprint, go to Theme Editor Option in your Dashboard, Find the file named "Footer.php" and remove the links. if you want to add different credit but you don't know PHP use w3c standard HTML queries to add footer links.
2.
Plugins: Most WordPress Plugins has footprints, linking back to developer's site. You can remove such footprints by editing the Plugins files, give credit to them with donation or post link to their website, another way to block plugin footprint is adding proper tags to your .htaccess file or disable directory indexing using robot.txt file
there are many way to do this using .htaccess
listed one example;
Code:
[COLOR=#ffffff]# Disable Directory Browsing
Options All -Indexes[/COLOR]
robot.txt example
Code:
[COLOR=#ffffff]User-Agent: *
Disallow: /wp-content/plugins/[/COLOR]
