Canada Post says 950,000 customers are at risk of data breach Canada’s national postal operator said a malware attack on one of its suppliers has affected 44 of the country’s largest corporate customers and could affect nearly 1 million people. Canada Post said in a statement on Wednesday that Commport Communications, one of its suppliers, was compromised in a cyber attack. Commport is a so-called electronic data interchange provider, which means it can manage shipping inventory data for large corporate customers. When shipping large packages, its system can access information such as the name and address of the sender and recipient.