Ransomware is the big threat to both individuals and companies in the UK at present. Home users are seeing emails with .doc or .pdf attachments which purport to be invoices from companies or other inviting subjects. The golden rule is never open the attachment. If you don't recognise the sender, delete the message. This goes for all emails from 'Apple' about people using your Apple ID or needing your sign in info. And if you think these things are insignificant, look what can happen. Read more here.