More Printers Could Mean Security Problems for Home-Bound Workers

As employees outfit their home offices with the necessary technology to continue to work remotely, printer sales have surged in the first eight months of 2020, leaving security experts to worry that the devices may open up companies' home-bound employees to attack.  

An analysis by consulting firm Deloitte estimates that 2020 may see a 15% increase in sales of printers, with many stores seeing massive increases in sales and a depletion in their stocks. Remote workers often do not use strong passwords to protect the administrator account and may not have up-to-date firmware on the devices, which leaves the printers as a way into their home network and — using lateral movement through a company's virtual private network — into the corporate network, says Bob Burnett, director of B2B solutions and deployment planning at printer maker Brother International. 

"The world changes a little bit moving to the home environment," he says. "Traditionally, if the user has put a device on their home network, they have a machine built for home use, and it may not have the security features of the same products deployed into the corporate network."

The threat is not theoretical.

At the end of August, a group of researchers sent a print job to a sampling of 50,000 of the 800,000 Internet-connected printers found through search engines such as Shodan.io, resulting in nearly 28,000 printers — or 56% of the discoverable devices — printing out their document, a single-page guide to securing the printer. The experiment of questionable legality led the group to conclude that about 450,000 printers are vulnerable to attack over the Internet.

Internet-connected printers are not the only danger. An increase in mobile devices has also led to an increase in Wi-Fi-enabled printers. Matt Lewis, research director for the United Kingdom at the security consultancy NCC Group, discovered that his neighbor's printer appeared in his list of Wi-Fi-accessible devices, prompting a friendly discussion about security. 

Such incidents highlight that printers should not be overlooked when companies, and their remote workers, think about security, he says.

"Knowing how many more printers have people bought and deployed to their homes, the worry is that they will be like other IoT devices — they are designed to get up and running easily, with security an afterthought," Lewis says. "That means the devices need to be hardened once out of the box, and that advice and guidance should be pushed a lot more to the home worker, at least by their employers."

At last year's DEF CON conference, researchers from the NCC Group publicly disclosed 49 vulnerabilities in printers from Brother, HP, Kyocera, Lexmark, Ricoh, and Xerox. In the past year, printer manufacturers have upped their security game, says NCC's Lewis, one of the researchers on the vulnerability project. 

"Most of the printer manufacturers have a mature attitude and realize that there is some work to do," he says. "You still have a legacy problem with printers, however, where business — and definitely consumers — use them for 10+ years."

The printer hacking exercise conducted by researchers at CyberNews in August underscores that there is still a large potential attack surface area. As of 2019, some 62% of households had a printer, according to Deloitte's analysis.

One positive for security: Printers used in home-office environments are often connected — not to the network but through a USB cable, making the devices harder to attack, says Brother's Burnett. USB-connected printers are much harder to compromise, because the attacker either has to have physical access to the printer or must compromise the device after hacking the victim's computer.

"A lot of corporations, because of the security concerns, worry about the network and still use USB," he says. "We have a lot of larger customers that had a large work-from-home workforce, and they mandate those machines are connected via USB and only used for work at home."

Burnett recommends that users check their firmware and make sure to set an administrator password. In addition, companies should scan their networks for open printer ports, he says.