New POS Malware Steals Data via DNS Traffic

Researchers at Forcepoint have discovered new point-of-sale (POS) malware disguised as a LogMeIn service pack that is designed to steal data from the magnetic stripe on the back of payment cards.

The malware, which Forcepoint is calling UDPoS, is somewhat different from the usual POS tools in that it uses UDP-based DNS traffic to sneak stolen credit and debit card data past firewalls and other security controls. It is also one of the few new POS malware tools to surface in some time, according to the company.

In recent years, the US, like many other countries, has switched from magnetic cards to chip and PIN cards based on the Europay, Mastercard, and Visa (EMV) standard. The transition has made it harder for criminals to steal payment card data using POS malware—like they did with the massive theft at Target in 2013.

However, malware like UDPoS suggests that criminals still see an opportunity to steal data from POS systems. For instance, Trend Micro last year reported on MajikPOS, a POS malware family that was used to steal data on more than 23,300 payment cards. Retailer Forever 21, which is investigating a data breach first reported last November, recently disclosed finding malware on some of its POS systems.

Luke Somerville, head of special investigations at Forcepoint, says there's no evidence to show that UDPoS is currently being used to steal credit or debit card data. But Forcepoint's tests have shown that the malware is indeed capable of doing so successfully.

In addition, one of the command and control servers with which the malware communicates was active and responsive during Forcepoint's investigation of the threat. "[This] implies that the authors were at least prepared to deploy this malware in the wild," Somerville says.

Among the likely targets of the malware are POS systems in hotels and restaurants and any other location with handheld devices for swiping credit and debit cards.

"This malware targets Windows-based systems," Somerville notes. "Legacy POS systems are often based on variations of the Windows XP kernel. Large retailers who have not recently updated their systems could potentially have hundreds or even thousands of vulnerable machines."

Forcepoint discovered the malware when investigating an apparent LogMeIn service pack that was generating a notable amount of unusual DNS requests. The company's analysis of the malware showed it contacting a command and control server that also had a LogMeIn-themed identity.

There is no evidence that LogMeIn's remote access service or products have been abused in any way as part of the malware deployment process, says Somerville. Instead, the authors of UDPoS appear to be simply using the LogMeIn brand as a sort of camouflage. "Using the name of a legitimate product as the theme of the file and service names is effectively an attempt to limit suspicion over the presence of these artifacts on infected machines," he says.

Forcepoint itself has no insight into the process that the malware authors have used or plan to use to deliver UDPoS on point-of-sale systems. But the use of the LogMeIn brand to disguise the malware is not accidental. Many retailers and other organizations use LogMeIn's software to enable remote management of their POS systems.

Given the filenames that have been chosen, it is clear that the authors of the malware are hoping to sneak their malware into these systems in the guise of a LogMeIn software update, Somerville says.

LogMeIn itself issued an alert this week warning its users not to fall for the scam. "According to our investigation, the malware is intended to deceive an unsuspecting user into executing a malicious email, link or file, possibly containing the LogMeIn name," the company noted.

The alert reminded organizations of the LogMeIn's policy of never using an attachment or a link for updating its software.

"UDPoS appears to have drawn inspiration from several other POS malware families," Somerville says. "While none of the individual features are entirely unique, the combination of them appears to be a deliberate attempt to draw together successful elements of other campaigns."

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