Back in January, arts and crafts retail giant Michaels announced that it was investigating a potential security breach, and now the company has confirmed that millions of credit cards may have been compromised by a cyberattack. The company says that the attack targeted its point-of-sale systems at a “varying number” of stores from May 8th, 2013 through January 27, 2014. Overall, some 2.6 million credit and debit cards may have been affected, which is about seven percent of cards used in its stores over that timeframe.