We reported last week that Oracle’s MICROS point-of-sale devices had been compromised. On the heels of the compromise, Visa sent out a security alert last Friday to merchants warning companies that use Oracle’s MICROS point-of-sale devices to check the machines for malicious software or unusual activity, and to change passwords on the devices.

The Visa alert indicates that although Oracle is investigating the situation, “Visa is issuing this alert to provide indicators of compromise (IOCs) associated with cybercrime threats known to have previously targeted Oracle systems.” The IOCs include a list of suspect Internet addresses, domain names, and other digital clues that connect the attacker with the victim. The IOCs can help MICROS customers track whether or not their point-of-sale system has been compromised by checking to see if there has been any communication between their system and the IOCs. Oracle MICROS customers may wish to check the IOCs with their company’s traffic to see if there is any communication, which may indicate a compromise.