However, iTWire understands that the attack was on Brookfield Residential, an investee site of the company.
Brookfield residential, which is based in Calgary, has assets of C$5.7 billion as per its second quarter report.
The ransomware used to effect the theft is a relatively new one known as DarkSide and, as usual, only attacks Windows systems.
iTWire understands that Brookfield Residential has alerted the appropriate authorities, restored affected systems taken additional steps to boost security.
The attackers claim to have stolen Brookfield data relating to corporate HR, finance, payroll, administration, business plans and commercial matters.
They claim the data is pre-loaded and ready to be published if Brookfield does not pay the ransom that has been demanded. Exactly how much is being sought has not been specified.
The website Bleeping Computer said in a report on 21 August that gangs using DarkSide were asking for ransoms ranging from US$200,000 to US$2 million.
The criminals have also said that after publication, the data will be available on the dark web for at least six months.