Menu
Apple computers vulnerable to 'Thunderstrike 2' firmware worm

Apple computers vulnerable to 'Thunderstrike 2' firmware worm

The improved attack highlights ongoing concerns over the security of a computer's low-level code

Some Apple computers are vulnerable to a firmware attack that could install difficult-to-remove malware, according to research to be presented at the Black Hat conference on Thursday.

Some Apple computers are vulnerable to a firmware attack that could install difficult-to-remove malware, according to research to be presented at the Black Hat conference on Thursday.

An improved attack on the firmware in Apple computers makes them vulnerable to hard-to-detect malware without even being connected to a network, according to a Black Hat conference presentation due to be given later this week.

The new research highlights ongoing weaknesses in the low-level software that runs on every computer before an operating system is loaded.

It comes from researchers Xeno Kovah and Corey Kallenberg of LegbaCore and Trammell Hudson of Two Sigma Investments. They showed earlier this year how they could infect a Mac's firmware with malware by connecting malicious devices to them using Thunderbolt, Apple's high-speed data transfer interface. The attack was dubbed Thunderstrike.

On Thursday, they will unveil Thunderstrike 2, an attack that improves on the former since it can spread to other machines through removable peripherals.

Their attack uses several vulnerabilities in firmware used by Apple. The company patched some of the flaws in June, but some remain, Hudson wrote on his blog.

In theory, firmware shouldn't be able to be modified or rewritten. Malware that sits within firmware is particularly dangerous since security products don't check the integrity of firmware, meaning users would have no idea it has been tampered with.

The Thunderstrike 2 attack uses a local root privilege exploit that loads a kernel module and gives it access to raw memory, according to a two-minute preview video posted by the researchers on YouTube.

In some cases, the attack code can immediately unlock and rewrite the boot flash firmware. In other instances it can take advantage of a problem when a computer is put into sleep mode and then resume running, a problem that has been explored by another researcher.

The malware can write itself to the Option ROMs of removable Thunderbolt peripherals. If an infected peripheral is inserted into another Mac, the Option ROM is executed before the OS's kernel launches.

It can't tamper with the firmware just yet, though. It has to wait for the computer to go to sleep and wake up again. After that happens, the boot flash isn't protected anymore, and Thunderstrike 2 can write itself to the firmware.

"Once installed in the boot flash, it is very difficult to remove since it controls the system from the very first instruction executed upon booting," the video says. "This includes the keys for updating the firmware."

Reinstalling the OS won't remove the malware and neither will replacing the hard drive.

The attack could be used to reach computers that have been intentionally isolated for security reasons. For example, a Mac could be infected using a Web-based attack. Then, Thunderstrike 2's code could infect a Thunderbolt peripheral. If that device is then inserted into an air-gapped machine, it's infected.

Send news tips and comments to jeremy_kirk@idg.com. Follow me on Twitter: @jeremy_kirk


Follow Us

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags AppleExploits / vulnerabilitiesLegbaCore

Featured

Slideshows

The making of an MSSP: a blueprint for growth in NZ

The making of an MSSP: a blueprint for growth in NZ

Partners are actively building out security practices and services to match, yet remain challenged by a lack of guidance in the market. This exclusive Reseller News Roundtable - in association with Sophos - assessed the making of an MSSP, outlining the blueprint for growth and how partners can differentiate in New Zealand.

The making of an MSSP: a blueprint for growth in NZ
Reseller News Platinum Club celebrates leading partners in 2018

Reseller News Platinum Club celebrates leading partners in 2018

The leading players of the New Zealand channel came together to celebrate a year of achievement at the inaugural Reseller News Platinum Club lunch in Auckland. Following the Reseller News Innovation Awards, Platinum Club provides a platform to showcase the top performing partners and start-ups of the past 12 months, with more than ​​50 organisations in the spotlight.​​​

Reseller News Platinum Club celebrates leading partners in 2018
Meet the top performing HP partners in NZ

Meet the top performing HP partners in NZ

HP has honoured its leading partners in New Zealand during 2018, following 12 months of growth through the local channel. Unveiled during the fourth running of the ceremony in Auckland, the awards recognise and celebrate excellence, growth, consistency and engagement of standout Kiwi partners.

Meet the top performing HP partners in NZ
Show Comments