Someone inserted a link on my blog theme

you need to go to header.php and remove this code <p>bet.webeden.</p> once the code is removed you need to change your FTP, HOsting, WOedpress backend details.

It’s possible that’s a plugin doing that, but you might also have been hacked. Your site is showing up clean on Securi, but you could still have malware. Try deactivating all your plugins – if that does not fix it, you should start working through these resources:
https://codex.www.ads-software.com/FAQ_My_site_was_hacked
https://www.ads-software.com/support/topic/268083#post-1065779
https://smackdown.blogsblogsblogs.com/2008/06/24/how-to-completely-clean-your-hacked-wordpress-installation/
https://ottopress.com/2009/hacked-wordpress-backdoors/

Additional Resources:
https://sitecheck.sucuri.net/scanner/
https://www.unmaskparasites.com/
https://blog.sucuri.net/2012/03/wordpress-understanding-its-true-vulnerability.html
https://codex.www.ads-software.com/Hardening_WordPress
https://www.studiopress.com/tips/wordpress-site-security.htm

Great, thank you!

I found the plugin and deatcivated it.
This was very smart, since it seems that it recognize the ip from which you admin the blog, and disabled the link appearence for that ip. In fact the link appear only when I come from new IPs.
So I had to change my ip to get this done.

By the way the plugin is Analytic (https://charlotte.byethost22.com/analytic/)
the funny part is that I don’t even remember I installed it, nor activated it, since I already have 2 stats plugin.

I think this is very bad, and should be shared to everyone.
Is there any place to do this?