APT28 – First UEFI Rootkit Seen in the Wild

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Yet another vector being exploited by miscreants is the APT28 rootkit which accesses your firmware BIOS settings/ UEFI. There is no known check for this and re-flashing your firmware/ UEFI or replacing your motherboard seems the only way to eradicate the rootkit!

Security researchers tracking the operations of a cyber-espionage group found the first evidence of a rootkit for the Unified Extensible Firmware Interface (UEFI) being used in the wild.
The threat actor, known in the infosec community by the names Sednit, Fancy Bear, APT28, Strontium, and Sofacy, was able to write a malicious component into a machine’s UEFI firmware.

More info over at bleepingcomputer with advice on a defending against this.

Windows - commercial by definition and now function...

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Replacing with a new motherboard is a fairly drastic action to consider!

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Elly, jburk07

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An alternative is to replace the motherboard with a newer generation since LoJax affects older chipsets. This requires some technical knowledge, to ensure hardware compatibility, and most users find it easier to replace the entire station.

Quoted from bleepingcomputer.com (my bolding)

That’s exactly what I though when I read it, surely the removal of motherboard battery for 10mins and new replacement BIOS chip and would be suffice in that scenario. It’s quite disturbing..

Section 7: Conclusion of the ESET pdf link below demonstrates the seriousness of this particular rootkit as well as the potential for future iterations.

https://www.welivesecurity.com/wp-content/uploads/2018/09/ESET-LoJax.pdf

UEFI rootkits are one of the most powerful tools in an attacker’s arsenal as they are persistent across OS re-install and hard disk changes and are extremely difficult to detect and remove.

Windows - commercial by definition and now function...

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Prevented by Secure Boot though, so Windows 8/10 are safe by default.

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AlexEiffel

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The malware requires Windows to run the program that installs the UEFI rootkit (it uses RWEverything, a legitimate program with signed drivers), and as the aforementioned article says, “The purpose of the rootkit is just to drop malware into the Windows operating system and make sure that it executes at startup.”

It requires Windows to install, and it requires Windows to do its evil deeds once installed.  So while safe boot may prevent the system from booting once the compromised firmware has been written, you’re still stuck with a PC that has compromised firmware and won’t boot.  I would not call that “safe,” although it certainly is safer than if it silently worked in the background and stole your data or whatever else it is supposed to do.

Not all installations of 8 and 10 would be safe(-ish) by default.  Those that came with 8 or 10 preinstalled would be, since that is the required default condition for preinstalled Windows, but those that were upgraded almost certainly will have it off (the owner will have had to take the initiative to enable it manually).

By contrast, Linux, though, would really be safe.  It won’t know how to run the RWEverything program, so the firmware won’t be compromised in the first place.

In addition, most or all major Linux distros and their derivatives will very happily allow secure boot.

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If there is no known check for this, can it really be called “seen in the wild?”

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There is no check for the rootkit in the UEFI, but the installer that carries that payload can be detected.

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Elly

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So the presence of an identified installer yields a high probability of successful infection, that makes sense. Is there a prevailing opinion yet on how limited or unbound the list of capable installers may be? That may communicate a sense of how dense the brush is in these wilds.

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Resident evil: Inside a UEFI rootkit used to spy on govts, made by you-know-who (hi, Russia)
Deep dive into motherboard firmware-lurking code

By John Leyden | 28 Sep 2018

 
A UEFI rootkit, believed to have been built by Kremlin spies from an anti-thief software program to snoop on European governments, has been publicly picked apart by researchers.
…
According to infosec biz ESET, a firmware rootkit dubbed LoJax targeted Windows PCs used by government organizations in the Balkans as well as in central and eastern Europe. The chief suspects behind the software nasty are the infamous Fancy Bear (aka Sednit aka Sofacy aka APT28) hacking crew, elsewhere identified as a unit of Russian military intelligence.

That’s the same Fancy Bear that’s said to have hacked the US Democratic Party’s servers, French telly network TV5, and others.
…
There are firmware settings that can thwart the flash installation simply by blocking write operations. If BIOS write-enable is off, BIOS lock-enable is on, and SMM BIOS write-protection is enabled, then the malware can’t write itself to the motherboard’s flash storage.

Alternatively, wiping the disk and firmware storage will get rid of this particular rootkit strain.

 
Read the full article here

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We’re told by ESET that Secure Boot, if enabled, should stop LoJax from injecting itself into the firmware storage,

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Kirsty wrote:

There are firmware settings that can thwart the flash installation simply by blocking write operations. If BIOS write-enable is off, BIOS lock-enable is on, and SMM BIOS write-protection is enabled, then the malware can’t write itself to the motherboard’s flash storage.

There was a time when it was common to have a jumper on the motherboard that would have to be removed in order to enable firmware flashing.  With the jumper in place, all that a user would be able to do is alter the NVRAM settings with a given BIOS version, but not flash the BIOS itself.

I guess this was too inconvenient, so now most PCs allow any flashing, any time.  At the very least, OEMs could include the jumper pinout (just two pins close to one another) and leave the jumper off, or in other words, in flash-allowed mode.  That way, to the user who is not about to open the PC and move the jumper, everything is the same, but to those of us who are not afraid of opening the case, more protection would be available.

Obviously, this would not work on the new breed of factory-sealed laptops that are never meant to be opened, but laptops that have the access covers for RAM, etc., or that are otherwise able to be opened, could easily have such a jumper.  Even my thin and light, all aluminum cased Acer Swift can be opened in a matter of minutes with the proper tools (T6 Torx screwdriver and a guitar pick, in my case).

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Unfortunately, the UEFI specification requires the hardware to have a writable flash area (called “variables”) where UEFI programs (that includes operating systems, recovery tools and this malware) can write information.  As a practical matter, many motherboards put this in the same flash chip as the BIOS itself and just relies on the BIOS code to decide what gets written where.

Another problem is that UEFI bioses tend to run the installed UEFI programs (boot) before checking if the user wants to open the configuration interface to change what gets run.  This saves the 2 seconds of boot time it takes to give the user a fighting chance to press the emergency stop key.

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From Weekly Threat Report 5th October 2018:

 
LoJax – A new type of rootkit

Security researchers at anti-virus software company ESET have revealed a new type of malware that is capable of surviving reinstallation of the Windows operating system or even hard drive replacement.

This type of clandestine rootkit is designed to provide continued privileged access to a computer while actively hiding its presence. This is the first time this type of malware has been seen ‘in the wild’.

The malware dubbed “LoJax” makes use of the Unified Extensible Firmware Interface (UEFI) which enables the connection of a computer’s firmware to its operating system and is largely replacing the Basic Input Output System (BIOS). Like BIOS, UEFI is installed at the time of manufacture and is the first program that runs when a computer is turned on. This enables LoJax to start every time the computer is booted.

The malware is based on an older version of a legitimate application called LoJack and/or Computrace, which enables stolen devices to be found. The code is hidden within the UEFI firmware and when started, connects to a command and control server over the internet.

The researchers have attributed LoJax to the threat group Sednit/Fancy Bear/APT28.

Removing the malware from an infected device involves updating (or re-flashing) the UEFI firmware, an operation not commonly done and certainly not by the typical user.

Infection prevention is easier than a cure. PCs with Windows 8 and 10 are shipped with a feature called “Secure Boot” enabled which is designed to prevent digitally unsigned software from hijacking the boot process and concealing itself from the operating system.

NCSC provides detailed guidance on the management of UEFI firmware settings which will almost certainly prevent this type of malware attack.

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