Sometimes Success-SEO.com can be listed in your AdSense Sites list as a site displaying your AdSense adverts. Success-SEO.com is listed in your AdSense sites list because at some point, Success-SEO.com has copied your AdSense code, put it on their website, then created a page impression.
Why would Success-SEO.com want to display your AdSense adverts, you are probably wondering? Well, it’s because Success-SEO.com wants you to see their website there. Success-SEO.com is owned by Semalt, which is a company that sells (legitimate or not?) SEO related services to webmasters. They are deliberately displaying your adverts on their website, then generating a fake impression (probably a bot) of the advert so it shows up in your AdSense reporting. Their plan is for you to see their website in their reporting, then visit it to find out what Success-SEO.com is. They then redirect you to their Semalt website, where they try to sell you SEO services.
The whole thing is really just a very clever and ingenuitive way to spam you.