Every time I open my e-mail account using BT Yahoo Mail an unexpected and uninvited tab appears next to the 'Contacts' tab. On the tab it says "tasty_waterfall63" and because I'm concerned it might be phishing, I hastily click the x to close it. A pop-up then appears saying that I have unsent messages and do I really want to close the conversation. I obviously click 'yes'. Does anyone know what it might be and how I get rid of it please?
Its just someone trying to contact you via Yahoo messenger, probably someone trying to sell you something. Just ignore it, and make sure your status is set to "invisible to everyone", then they cannot see you are online.