At long last, it appears investigators have found the cause of the Target breach. The retailing giant last week revealed that the source of the costly drama was connected to network credentials stolen from a third-party vendor.
Now, KrebsOnSecurity is reporting that the vendor in question was a refrigeration, heating and air conditioning subcontractor that has worked at a number of locations at Target and other top retailers. Brian Krebs, a security blogger, said sources close to the investigation claim the attackers first broke into the retailer’s network on Nov. 15, 2013 using network credentials stolen from Fazio Mechanical Services, an HVAC systems provider. Target has not officially issued a statement.
“Fazio president Ross Fazio confirmed that the U.S. Secret Service visited his company’s offices in connection with the Target investigation, but said he was not present when the visit occurred,” Krebs said on his blog. “Fazio Vice President Daniel Mitsch declined to answer questions about the visit. According to the company’s homepage, Fazio Mechanical also has done refrigeration and HVAC projects for specific Trader Joe’s, Whole Foods and BJ’s Wholesale Club locations in Pennsylvania, Maryland, Ohio, Virginia and West Virginia.”
We caught up with Dwayne Melancon, chief technology officer for security software firm Tripwire, to get his take on the latest Target breach revelations. He told us this is something you'll see a lot more of in the evolving "Internet of Things" world.
“HVAC's are IP-addressable appliances now, which means they have network access and logins. It wouldn't be unusual for contractors to have an HVAC login,” Melancon said. “The trouble is that a lot of people implementing ‘smart devices’ do not recognize the security risks of placing them on a production network where they can access other sensitive or systems.”
As he sees it, this is yet another example of the need for security professionals to take a step back and look at the overall ecosystem of devices and how they are connected. Attackers will find and exploit the weakest link in an interconnected network every time, he predicted.
“One thing that isn't known about this attack: were the same credentials for the HVAC system used on other devices in the network?” he asked. “If so, that is what I would call a ‘rookie mistake.’"
Who’s To Blame?
We also turned to Lamar Bailey, director of security at Tripwire, to seek his opinion on the HVAC contractor connection. He told us all commercial HVAC systems are computer controlled today and the temperature for most big, commercial buildings is set based on time of day and proximity sensors and requires computer access to the controls.
“If there was something wrong with the HVAC settings in one of Target’s properties, they would probably call a contractor, and it’s entirely possible that a repairman with a laptop would need to log on to the network where the HVAC controls are located to troubleshoot the problem,” he said.
If Target had other network systems, especially the patch delivery server for the POS devices or the POS devices themselves, on the same segment of the network where the contractor logged in it would be relatively simple to infect the network with malware, he explained.
“The contractor may not have known his laptop was compromised with malware, or he could have been one of the lynchpins in the attack,” Bailey said. “We’ve certainly seen enough movies where the plot hinges on a guy with a clipboard using a repairman ruse to get inside an organization. Based on what we know about this breach that scenario is completely plausible.”