Lorenz ransomware responsible for the breach
https://www.bleepingcomputer.com/news/security/canada-post-suffers-data-breach-after-supplier-ransomware-attack/
Canada Post has informed 44 of its large commercial customers that a ransomware attack on a third-party service provider exposed shipping information for their customers.
Canada Post is the primary postal operator in Canada, serving 16.5 million Canadian residential and business addresses.