Internal LTE/3G modems can be hacked to help malware survive OS reinstalls

Researchers found a way to write malicious firmware to a popular LTE/3G modem module built into business laptops and tablets

Victim of identity theft

Victim of identity theft

With their own dedicated processor and operating system, LTE/3G modems built into new business laptops and tablets could be a valuable target for hackers by providing a stealthy way to maintain persistent access to an infected device.

In a presentation Saturday at the DEF CON security conference in Las Vegas, researchers Mickey Shkatov and Jesse Michael from Intel's security group demonstrated how a malware program installed on a computer could rewrite the firmware of a popular Huawei LTE modem module that's included in many devices.

The module runs a Linux-based OS, more specifically a modification of Android, that is completely independent from the computer's main operating system. It's connected to the computer through an internal USB interface, which means that it could be instructed to emulate a keyboard, mouse, CD-ROM drive, network card, or other USB device. Those would appear connected to the primary OS.

The main problem found by the Intel researchers was that the update process for the modem's firmware was insecure, lacking a cryptographic signature verification. This allowed them to create a malicious firmware image that could be written through the Windows update utility provided by the vendor.

The malicious firmware could be flashed by a malicious program that already runs on the computer, or by users themselves if an attacker tricks them into thinking that a new update is available.

If successful, the attack would provide a way to reinfect the main OS even if it is reinstalled. Moreover, the rogue firmware could be modified to ignore any subsequent firmware update requests, leaving the user with no option to recover from such a compromise, except for taking his laptop or tablet apart and pulling out the infected modem module.

Huawei has addressed the issue and the module now performs a secure boot, preventing the use of unauthorized firmware images, the researchers said, adding that the company has been very responsive and great to work with.

There is a platform risk with these modems and other components that provide independent execution environments where malware can survive OS wiping and which are not visible to antivirus and other security programs. That's why secure software updates are really important, the researchers said.

Join the PC World newsletter!

Error: Please check your email address.

Tags HuaweiintrusionDefconsecurityExploits / vulnerabilitiesintelmalware

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?