A cybersecurity expert says a systems breach at Suncor Energy Inc. will likely cost the company millions of dollars before the issue is resolved.

Jon Ferguson of the Canadian Internet Registration Authority says the type and scale of the cyberattack currently affecting the Calgary-based oil and gas company remains unknown.

Suncor confirmed the attack Sunday, but has declined to comment further.

But Ferguson says companies who fall victim to cyber crime face extensive costs to clean up the damage — everything from possible ransomware payments to the hiring of lawyers, data breach coaches and third-party IT experts.

The cyberattack affected many of Suncor's Petro-Canada sites across the country over the weekend, and many remain unable to accept credit or debit payments.

Ferguson says the cost of the breach will also include lost revenue as a result of customers who choose to fill up elsewhere, as well as reputational damage to Suncor's brand.

This report by The Canadian Press was first published June 27, 2023.