It would be interesting to know how this happened - I expect that it was just an email slipping through the virus checks. Releasing the "how it happened" information would help other people prevent this from happening to them - every day I see emails arrive with interesting attachments:
P.O 567934.zip (P.O 567934.exe) , 0072635_20200713_pdf.ace, PON991197.doc, Payment details.zip (Payment details.exe), Invoice_376102_INC.xlsm, English_Court OrderCASE#036886890678.iso, etc.
Biting the hand that feeds IT
