Home Depot credit card security breach could cost $3B

The theft of credit card information from Home Depot by hackers earlier this year could affect up to 60 million customers and lead to as much as $3 billion in bogus purchases, a major credit protection firm says.

Earlier this month, the home improvement retailer saidits networks were accessed by unknown hackers for an unknown amount of time earlier this year. Home Depot has confirmed that all of the chain's 2,200 stores in the U.S. and Canadamay have been hit, but so far the chain has declined to reveal how big the breach was.

• Home Depot hack: What do you do if your card was breached
• Canadians could be affected by Home Depot security breach

After looking at more than a dozen similar breaches this year and assessing what happened in those instances, credit protection firm BillGuardsays millions of people could be affected by thebreach that will likely lead to billions of dollars in bogus charges.

"We believethat approximately60 million accounts were exposed in the Home Depot breach, and estimatethat$2-3 billion in fraudis likely to strikethese compromised accountsoverall," the company saidin a post on its website last week.

Not all of those 60 million cardholders will necessarily see bogus charges, however. Only about 10 to15 per cent of them are likely to see any fraudulent activity, BillGuard says, with an average cost expected to be around $332 each.

• Home Depot braces for fallout from credit card breach

"BillGuard users are reporting fraudulent charges from a variety of sources, both online and brick-and-mortar," the company says. "Charges range from the five dollar range to tens of thousands of dollars. Some report a single fraudulent charge at one merchant, while otherswere hit by multiple charges frommultiple merchants."

Home Depot is offering identity protection services, including credit monitoring, to any customer who has shopped at a Home Depot store in 2014, from April onward. But cybersecurity expertsadvise customersto keep a keen eye on their credit card activityhistory and watch out for any curious transactions.