Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Malware & Threats

USB Device Firmware Can Be Reprogrammed to Hide Sophisticated Malware

Researchers Develop “BadUSB” to Demonstrate Extreme Threats Posed by USB Devices

Users have long been warned about the dangers of using USB drives, but new research shows significant threats that stem from USB devices that go far beyond thumb drives.

Researchers Develop “BadUSB” to Demonstrate Extreme Threats Posed by USB Devices

Users have long been warned about the dangers of using USB drives, but new research shows significant threats that stem from USB devices that go far beyond thumb drives.

Most security solutions can easily identify and neutralize a piece of malware that’s found on a USB device, but things get complicated if the threat resides directly in the firmware of such devices.

Dangers of USB Devices and Flash DrivesAt the upcoming Black Hat security conference, Karsten Nohl and Jakob Lell, both researchers at Germany-based SRLabs, will present a new type of malware which leverages the fact that the firmware found in thumb drives and other USB devices can be reprogrammed and abused for malicious purposes.

The problem, according to the researchers, is that the USB controller chips in peripherals can be reprogrammed to spoof other devices and there’s little or no protection to prevent anyone from doing so. In order to demonstrate their findings, Nohl and Lell have developed BadUSB, a self-replicating piece of malware that can be used by an attacker to take control of a computer.

For instance, the BadUSB malware can make a device emulate a keyboard and use it to send commands on behalf of the victim. Attackers can steal data, install other pieces of malware, and even infect the controller chips of other USB devices connected to the affected computer, SRLabs said in a blog post.

USB devices can also be reprogrammed to spoof a network card, allowing the attackers to change the infected computer’s DNS settings in an effort to redirect traffic. Thumb drives or external hard disks can be configured to detect when a computer is starting, and load a small virus into the operating system before boot. All of these scenarios will be demonstrated by the researchers at the Black Hat conference.

Nohl told SecurityWeek that they’ve implemented their attacks on one type of USB2 chip, one type of USB3 chip, and on Android phones. The controller chip firmware on which they’ve conducted their tests is very widespread and it’s used in the thumb drives produced by various companies, the researcher explained.

“Any device connected over USB could become a BadUSB by re-programming its USB controller. Whether and how that is possible differs by controller chip,” Nohl said via email.

Advertisement. Scroll to continue reading.

According to Nohl, SRLabs spent three months on reverse engineering and reprogramming the two USB controller chips on which they have conducted experiments.

These types of threats are not detected by security solutions because malware scanners can’t access the firmware running on USB devices. Behavior-based scanners aren’t efficient either because devices infected with BadUSB don’t exhibit any suspicious behavior. Instead, when the malware changes the functionality of a drive, it simply looks like the user plugged in a new device.

“To make matters worse, cleanup after an incident is hard: Simply reinstalling the operating system – the standard response to otherwise ineradicable malware – does not address BadUSB infections at their root. The USB thumb drive, from which the operating system is reinstalled, may already be infected, as may the hardwired webcam or other USB components inside the computer. A BadUSB device may even have replaced the computer’s BIOS – again by emulating a keyboard and unlocking a hidden file on the USB thumb drive,” SRLabs explained in its blog post. “Once infected, computers and their USB peripherals can never be trusted again.”

These attack techniques might seem new, but it’s possible that they’ve already been leveraged in the wild. Documents leaked by former NSA contractor Edward Snowden in December 2013 show that the intelligence agency has been using similar methods in its surveillance operations.

Written By

Eduard Kovacs (@EduardKovacs) is a managing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Understand how to go beyond effectively communicating new security strategies and recommendations.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Cybercrime

The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.

Cybercrime

A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...

Malware & Threats

The NSA and FBI warn that a Chinese state-sponsored APT called BlackTech is hacking into network edge devices and using firmware implants to silently...

Application Security

Virtualization technology giant VMware on Tuesday shipped urgent updates to fix a trio of security problems in multiple software products, including a virtual machine...

Malware & Threats

Unpatched and unprotected VMware ESXi servers worldwide have been targeted in a ransomware attack exploiting a vulnerability patched in 2021.

Cyberwarfare

An engineer recruited by intelligence services reportedly used a water pump to deliver Stuxnet, which reportedly cost $1-2 billion to develop.

Malware & Threats

Apple’s cat-and-mouse struggles with zero-day exploits on its flagship iOS platform is showing no signs of slowing down.

Cybercrime

No one combatting cybercrime knows everything, but everyone in the battle has some intelligence to contribute to the larger knowledge base.