On 27 June 2017, a piece of malware raced across the globe and took out many organisations including some that were similar to the one I was employed at. But we were safe and, in fact, not worried at all. All thanks to clever use of spreadsheets. In this talk, given entirely within Excel (yes, really) I go through the methods used to protect the organisation from this malware. If a talk given entirely in Excel sounds boring - you haven't seen this talk.