There was a “digital storm” brewing in CRA headquarters over this past weekend as CRA shutdown Services Due To Cyber Attack Link: https://www.cbc.ca/news/politics/canada-revenue-agency-cra-cyberattack-1.5688163
The first cyber-attack took place on August 7th. There were several attacks thereafter. Individual CRA accounts were targeted where the hackers would either apply for CERB or re-direct CERB applications to a different bank account.
CRA is contacting affected users