Are virus pop ups I’m safari real?

My iPad and iPhone are linked Together and for about 1 year my iPad gets various pop ups when using safari claiming I have a virus and it could damage my sim card. I thought this funny as my iPad has not got a SIM card in it however I have just received a pop up on safari on my iPhone claiming that a birus from an iPad has spread. Is this a con or what? This pop up has left me with a number and app to download to pay weekly bills to remove the virus. Is it real?