Third-party forensic experts have discovered that the point-of-sale systems in 54 Starwood hotels across the US and Canada were infected with malware. The company has listed all the locations in its PSA, including various Sheraton, Westin and W properties. That list also notes the possible dates (ranging from November 2014 to October 2015) when each location could have been compromised, and they were all before the hotel chain announced its acquisition by Marriott. Just like what happened to Hilton earlier this year, you might have only been affected if you used your credit cards in one of the 54 hotels' restaurants or gifts shops. Starwood America president Sergio Rivera says there's no evidence that its guest reservation and membership systems also had a security flaw.