Just received an invoice by email. Apart from the fact that the email doesn't say which company the invoice is from, what made me suspicious is that the attached file is a Word document which no-one would ever send out if it was genuine. Knowing that Word files can contain nasty macros and other surprises, the email has just gone straight in the bin.
You are quite right to bin this. This macro invoice with TRISTRA or similar completely wipes the files on your hard drive. You dodged a big bullet .