bankworm

Our School canteen has asked us to only submit food orders by internet so they have sent all parents a website that we have to join in order to make lunch orders I went to the site and then proceeded to make a user name etc and this window popped up saying i had now downloaded a Bankworm to my computer and i had to click on a McAcvee i think it was to get rid of it - which i did

how do i know if this is a true ? Fid i download a virus

I thought Apple computers di not get virus's

I know nothing about computers (obviously)

Are my bank details and passwords now at risk ?

what do i do should i ring the bank and get them to stop all transactions ?

Please help

jC