Malware Makes Itself at Home in Set-Top Boxes

"Free" can be an almost irresistible lure for consumers. When criminals use that lure in the form of television set-top boxes that promise free access to premium channels and services, they can entice many consumers into a trap that takes log-in credentials, private information, and financial data in return for the latest binge-worthy programming.

A new report from the Digital Citizens Alliance (DCA) says about 12 million people are using devices that promise illicit access to streaming services. The hackers taking advantage of those users follow a classic pattern in their activity. "[They] bait consumers with offers of free content, infect those that take the bait with malware, and steal vital personal information," the report states.

According to Tom Galvin, executive director of DCA, the problem is not with the hardware of the set-top boxes, many of which are used to host legitimate applications for accessing streaming services. The issue is with the applications that a criminal can load onto the hardware before it's delivered to the consumer.

These boxes, known as "Kodi boxes" for the Android open-source media player that serves as the software hub inside the device, are sold on Craigslist, Amazon, Ebay, and local for-sale websites. "Sandvine has estimated that almost 10% of the homes in North America are using a [Kodi box]," Galvin says. "They figure about 70% of those devices are configured to access unlicensed content." And it's in the apps that allow unlicensed access that the study found malware.

"At least 40% of the apps we evaluated were infected," says Timber Wolfe, owner of Dark Wolfe Consulting, which worked with DCA on the study. Wolfe executed malware found on one box in a controlled environment and then did reverse-engineering on the software. The first thing the software did was contact a server and update to a new version.

"As soon as it updated, it started exhibiting bad behavior," Wolfe says. "It looked for free file shares on my network, uploaded that data to a server, and immediately stole my Wi-Fi credentials," he explains.

Ultimately, the malware uploaded 1.5 terabytes of data from an available file share while it continuously looked for other file shares and unprotected devices on the network. In addition, it specifically looked for other malware.

"It's called 'port knocking," Wolfe says. "It was knocking on my Western Digital 4100 looking specifically for another malware family to open up a port and talk to it."

One of the great dangers of these schemes, beyond the threat to consumer privacy, is that the network-attached devices people use at home and then take to work become attack surfaces hackers can use to get into the corporate network, Galvin says.

Because the boxes themselves aren't illegal, protection from the malware they carry is complicated. "It's a combination of consumer awareness, law enforcement, and making sure that those who have sensitive information are aware of the risks here," Galvin says.

That consumer awareness may be the most important point. "When they put this machine on the network, they have allowed the hacker to bypass most of their security," Galvin says. "They've just escorted the hacker behind the firewall."

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