Although it looks like Conti operations are stopped, the members of the gang are joining different operations to continue attacks. According to Eclypsium, an individual started leaking information from the Conti ransomware group. The leaks confirm the connections between Conti and the Russian FSB.
Targeting Intel Management Engine
The leaks also show that the gang is focusing on firmware-based attacks. Attackers are now targetting Intel Management Engine or Intel Converged Security Management Engine instead of classical attacks that target UEFI/BIOS directly. ME is a physical microcontroller and a part of the chipset. There are several different variations of this component, such as Management Engine, Intel Converged Security and Management Engine, and Intel Trusted Execution Environment. There is also an alternate firmware family used in servers, Server Platform Services.
According to the leaked information, Conti is using the unique privileges of the ME firmware as a way to gain indirect access to the UEFI/BIOS. It allows attackers to drop additional payloads, and gain runtime control of the system below the operating system using System Management Mode. It can cause irreparable damage to a system or establish ongoing persistence that is invisible to the operating system.
Conti group claims that they already had developed proof-of-concept code for these methods nine months ago. Eclypsium shared its insight into ME firmware to help organizations. Analysis includes:
- Chipset Vulnerabilities – While it is known that these adversaries are actively analyzing the ME for new vulnerabilities, we wanted to identify the known vulnerabilities that attackers could use so that organizations can reduce their firmware attack surface.
- Attack Flow and Scenarios – We show different attack scenarios based on the low-level settings and protections set on a system, including in cases where the BIOS is properly write-protected.
- Attacker Objectives and Impact Analysis – Review of how attackers can use the ME and system firmware to achieve the greatest possible damage and impact to target organizations.
- Mitigations and Best Practices – Key steps that organizations should be taking today to defend their devices from these and similar threats.
When considering how a real-world attack would take place, there are several aspects Eclypsium has detected.
- Attacker gains access to a target host – This can be done via any number of common methods (either local or remote), whether via spear-phishing, exploiting a common OS or application vulnerability, an insider, or during any phase of the distribution, warehousing, or delivery phase of the device’s supply chain lifecycle.
- Attacker gains control over ME – This would be done either by a new 0-day vulnerability or via known vulnerabilities that provide remote code execution (RCE) and privilege escalation (PE). Because some of the ME vulnerabilities can be exploited remotely, this can make the previous step optional and an attacker can directly gain control of the ME without first exploiting a vulnerability in the host side of the platform.
- Use ME to rewrite UEFI/BIOS or gain SMM Execution – The ME firmware is inside the UEFI Trusted Computing Base (TCB), which opens the potential for an attacker to infect the UEFI from the ME. Attackers just need to bypass SPI Descriptor and BIOS Control register protections. We will look at multiple scenarios showing how this would work in a real attack.
Eclypsium also stated,
« The recent Conti leaks mark a critical phase in the rapidly evolving role of firmware in modern attacks. Threats such as TrickBoot, MosaicRegressor, and dozens of new forms of wiper malware have continued to drive attacks below the level of the operating system. However, the Conti leaks exposed a strategic shift that moves firmware attacks even further away from the prying eyes of traditional security tools. The shift to ME firmware gives attackers a far larger pool of potential victims to attack, and a new avenue to reaching the most privileged code and execution modes available on modern systems.
As the realities of the threat landscape continue to evolve, it is critical that organizations continue to inform their defenses based on the latest intelligence available. The Eclypsium team will continue to strive to provide updated insight and guidance into these and other firmware threats as they become available. »