Canada suffered just one severe weather event in March, but insured losses were extensive.
The company will acquire the private client investment management business of a firm based in Edinburgh, Scotland.
The new firm, with offices in Ontario and British Columbia, employs more than 100 employees.
Rating agency does not expect to downgrade insurers following this incident.
Hartford Financial Services Group Inc. rejected Chubb's unsolicited proposal to acquire the company.
Increases have reached 20 per cent.
The attack has caused a network disruption and impacted systems.