Black Hat Vegas: Where the Guardians of the BIOS Are Failing
By Alex Matrosov
In our upcoming Black Hat Vegas talk, we will summarize our research about the UEFI firmware protections and our newly-discovered security problems. This talk raises awareness of these security challenges for hardware vendors, BIOS-level security researchers and defenders, and sophisticated stakeholders who want to know the current state of UEFI exposure and threats. The situation is serious but, with the right tools and knowledge, we can prevail.[…]
It must be big if CERT notices a UEFI issue! 🙂
Table of Contents
Chapter 1: Observing Rootkit Infections
Chapter 2: What’s in a Rootkit: The TDL3 Case Study (NOW AVAILABLE)
Chapter 3: Festi Rootkit: The Most Advanced Spam Bot (NOW AVAILABLE)
Chapter 4: Bootkit Background and History (NOW AVAILABLE)
Chapter 5: Operating System Boot Process Essentials (NOW AVAILABLE)
Chapter 6: Boot Process Security (NOW AVAILABLE)
Chapter 7: Bootkit Infection Techniques (NOW AVAILABLE)
Chapter 8: Static Analysis of a Bootkit Using IDA Pro (NOW AVAILABLE)
Chapter 9: Bootkit Dynamic Analysis: Emulation and Virtualization (NOW AVAILABLE)
Chapter 10: Evolving from MBR to VBR Bootkits: Olmasco (NOW AVAILABLE)
Chapter 11: IPL Bootkits: Rovnix & Carberp (NOW AVAILABLE)
Chapter 12: Gapz: Advanced VBR Infection (NOW AVAILABLE)
Chapter 13: Rise of MBR Ransomware (NOW AVAILABLE)
Chapter 14: UEFI Boot vs. the MBR/VBR Boot Process (NOW AVAILABLE)
Chapter 15: Contemporary UEFI Bootkits
Chapter 16: UEFI Firmware Vulnerabilities
Chapter 17: How Secure Boot Works
Chapter 18: HiddenFsReader: Bootkits Forensic Approaches
Chapter 19: CHIPsec: BIOS/UEFI Forensics
The UEFI Firmware Rootkits: Myths and Reality
Alex Matrosov | Principal Research Scientist, Cylance
Eugene Rodionov | Senior Specialized Software Engineer, ESET
In recent days, the topic of UEFI firmware security is very hot. There is a long list of publications that have appeared over the last few years discussing disclosed vulnerabilities in UEFI firmware. These vulnerabilities allows an attacker to compromise the system at one of the most privileged levels and gain complete control over the victim’s system. In this presentation, authors will take a look at the state of the art attacks against UEFI firmware from practical point of view and analyze applicability of disclosed attacks in real life scenarios: whether these vulnerabilities can be easily used in real-world rootkits (OS->SMM->SPI Flash).
In the first part of the presentation, the authors will dive into different types of vulnerabilities and attacks against UEFI firmware to summarize and systematize known attacks: whether the vulnerability targets one specific firmware vendor, whether an attacker needs physical access to the victims platform and so on. Such a classification is useful to understand possibilities of an attacker. The authors will also look at the attacks and determine whether it can be converted into a real-world rootkit or the possibilities of the attacker are very limited and the attack vector cannot make it beyond the PoC.
In the second part of the presentation, the authors will look at defensive technologies and how can one reduce severity of some attacks. In modern Intel-based platforms implemented different methods and mitigation technologies against firmware and boot process attacks. The Boot Guard – hardware-based integrity protection technology that provided new levels of configurable boot: Measured Boot and Verified Boot (supported from MS Windows 8). The technologies responsible for platform flash memory protection from malicious modifications not a new trend. As example BIOS Write Enable bit (BIOSWE) has been introduced long time ago for made read-only access of flash memory. Another protection technology is BIOS Lock Enable bit (BLE) which is control every privileged code execution from System Management Mode (SMM) on each attempt to change BIOSWE bit. Also SMM based write protection (SMM_BWP) protects an entire BIOS region from unprivileged code (non-SMM) modifications attempts. One of the latest security technologies is SPI Protected Ranges (PRx) which can be configured to protect memory ranges of flash memory on the BIOS/platform developers side. The BIOS Guard (delivered since Skylake CPU) – is the most recent technology for platform armoring protection from firmware flash storage malicious modifications. Even if an attacker has access for modifying flash memory BIOS Guard can prevent execution of malicious code and protect flash memory from malicious modifications. Authors will analyse how these technologies can counteract existing firmware vulnerabilities and attacks.
If you haven’t heard of this book yet, see the Nostarch tags for a few older posts.