|By Albert Fruz||
|January 3, 2014 09:00 AM EST||
Computer security has become much harder to manage in recent years, and this is due to the fact that attackers continuously come up with new and more effective ways to attack our systems. As attackers become increasingly sophisticated we as security professionals must ensure that they do not have free rein over the systems that we are hired to protect. An attack vector that many people forget to consider is the boot process, which is almost completely controlled by the BIOS.
The BIOS is a privileged piece of software that is generally ignored by day-to-day users and thus they are usually unable to comprehend the importance of it in our computers. The Basic Input/Output System was first invented by Gary Kildall for use in his operating system CP/M and this became what we now know as the conventional BIOS system. The BIOS appeared in IBM-compatible PCs around 1975 and was used extensively in the CP/M operating system. This was later used in the MSDOS systems where it was known as DOS BIOS. These systems were only responsible for basic preboot hardware initializations before handing over control to the bootloader. This was fine 30 years ago, when software was simpler and attacks were not very predominant, thus the BIOS was not designed with security in mind. However, in today's world this is no longer the case. BIOS security lacks several features that make it vulnerable to external attack.
These are some notable attacks carried out against BIOS systems:
Chernobyl Attack (1998) - Also known as CIH or Spacefiller was the first major attack on BIOS systems. This virus installs on the windows memory and hooks into file access calls and infects all the currently executing programs. Then the virus tries to flash the BIOS rom by filling it with zeros. The other payload infects the Master Boot Record (MBR) by filling the first megabyte of the hard disk with zeros.
Mebromi (2012) - Is made up of a BIOS rootkit, MBR rootkit, Trojan downloader and PE infector. This Trojan deletes a specific registry value and checks for the BIOS manufacturer. If it's Award BIOS, it then infects the BIOS ROM and in turn infects the Master BOOT Record (MBR) and alters it allowing the execution of an infected program at each Operating System start-up.
We attempt to prevent such attacks by outlining several attack vectors and also suggest several mechanisms for the mitigation of attacks against the BIOS.
BIOS (Basic Input Output System)
Basic Input/Output System (BIOS), also known as the system BIOS or ROM BIOS, is a standard defining a firmware interface. BIOS software is built into the PC, and is the first software run by a PC when powered on. The fundamental purposes of the BIOS are to initialize and test the system hardware components, and to start the boot loader or an operating system from a secondary storage device. It also takes care of essential system functions such as power management and temperature regulation. It provides an abstraction layer for the underlying hardware by providing a consistent way for operating systems and application programs to interact with various input/output devices.
Changes in system hardware are abstracted by the BIOS from programs that use BIOS services instead of directly accessing the hardware. BIOS software is stored on a non-volatile ROM chip on the motherboard. Its unique design makes it compatible for particular models of computer, interfacing with various devices that make up the complementary chipset of the system. In modern PCs the BIOS contents are stored on an EEPROM chip.
An EEPROM chip or Electronically Erasable Programmable Read only memory is a type of non-volatile memory used by many electronic devices that requires small amounts of data to be stored for quick access. The contents of an EEPROM chip can be flashed, i.e., they can be overwritten with new data. This allows BIOS software to be easily upgraded to add new features and bug fixes. This feature is also one of the reasons that BIOS chipsets are vulnerable to attack.
Why BIOS Is in Blue
Most BIOS Screens will be blue; this is due to how the BIOS Manufacturers implement general BIOS color attributes. BIOS Color Attributes are 8-bit values where the lower 4 bits represent the character color and the higher 4 bits represent the background color. In BIOS, to print a white character in blue background the ‘BIOS colour attribute' would be set to a hexadecimal value of 0x1F.
Under certain conditions, setting the highest bit of the background color may cause the text to blink instead of making the background color intensified. In this context the highest bit of the background color should be kept low according to the BIOS color attribute distribution. As a result the Blue color which comprises value '1′ in hexadecimal is generally used for an uninterrupted BIOS display with intensified background with clear text.
Top BIOS Manufacturers
BIOS software is developed by several companies around the world and are usually deeply integrated with the system motherboard. Several of the most popular BIOS manufacturers are:
- American Mega Trends
Role of BIOS
The BIOS has an essential role in the boot process of the computer also known as bootstrapping. It initializes system hardware, manages ACPI, and regulates CPU temperatures during the booting process. The major responsibilities of the BIOS are listed below:
- Establish Trust: The BIOS is responsible for verifying the integrity of all the hardware components in the system and also to authenticate them before use. This is done with the help of Core Root of Trust Measurement (CRTM), which basically checks if the hardware is valid and that its integrity has not been compromised.
- Test Hardware: The secondary functionality of the BIOS is to initialize and test the hardware present on the computer before it's used. Hardware such as the motherboard, chipset and memory are included in this test. This is generally carried out during POST (Power-On-Self-Test).
- Load additional Modules: Several devices present on the computer may require additional firmware for its proper functioning. The BIOS ensures that such additional firmware modules are loaded and executed. These may be stored in the BIOS chip itself or some secondary storage device.
- Boot Device Selection: After the above steps have been carried out, the BIOS starts to detect a valid boot device, e.g., USB drives, dard disk, etc. Once such a device has been found it executes the bootloader found on that device.
- Start Operating System: After this the actual bootstrapping process begins, the bootloader starts to execute and begins to load the OS kernel into memory. Once the kernel has been initialized the BIOS transfers full control to the Operating System.
System BIOS can be of two types namely:
- Legacy BIOS
- BIOS based upon the UEFI specification
Conventional BIOS (Legacy BIOS)
The Legacy BIOS or conventional BIOS is the tried and true BIOS type that has been around for years. It's generally a 16-bit program that is flashed onto a ROM chip and placed in the motherboard of the computer. This type of BIOS is very outdated and more vulnerable to attack, therefore it's advisable to use a newer and more stable specification.
The key component in conventional BIOS is a boot block. This part is logically separated from other parts of the BIOS and initially executed during the BIOS boot process. Then the boot block checks the integrity of the remaining firmware in BIOS and if any is corrupted recovers those. The boot block then initializes almost all the hardware associated with the system by using a Power-On-Self-Test (POST). During this procedure low-level hardware components like Memory, CPU, Chipset, etc., are initialized.
After this process, it then loads other option ROMS like Video Cards, SCSI Controller Cards, and Network Boot ROM that have their own BIOS software. This Option ROMS could inform the BIOS about its functionality, and then it could be called later on in the boot process depending on the order the user had selected. Then the BIOS checks the Master BOOT Record (MBR) in the order of the boot device's priority. If any storage device has a valid data that relates to MBR, it is selected. MBR then points to a corresponding boot loader of an operating system and thus in turns loads the operating system.
In a conventional Boot process, the System Management Mode (SMM) can be initiated by using SMI handlers and ACPI table's code. System Management Mode is a 32-bit mode that runs on high-privileged mode that can override almost all the hardware security mechanisms of the protected mode. In order to change to SMM mode, BIOS loads SMI handlers and initializes the ACPI tables and codes
Legacy BIOS Boot Process
When a computer is first powered on the BIOS is the first piece of software that is executed. The boot block then executes a POST (Power-On-Self-Test), thereby ensuring that all the hardware on the system is valid and accounted for. After the POST screen the user has the option to load the BIOS screen or to continue booting the current operating system instead. This is done by pressing a pre-designated key on the keyboard. This key may vary depending on the BIOS manufacturer. The BIOS then checks if any additional pieces of firmware have to be loaded for individual devices on the computer if so, then these modules are loaded and executed.
Unified Extensible Firmware Interface (UEFI)
UEFI (Unified Extensible Firmware Interface) is a specification that was first designed by Intel in the 1990s for its Itanium range of computer systems. It was originally called the EFI specification and was intended to be a better replacement for legacy BIOS systems. UEFI has several advantages over the conventional BIOS and is radically different from these older systems.
The UEFI specification defines a programmable software interface that lies between the device firmware and the operating system. It provides an almost OS-like interface to device firmware. Depending on the manufacturer it may lie on top of the BIOS but it's generally placed in the /EFI/ directory on some form of non-volatile memory. This may either be a NAND chip on the motherboard, a hard drive or even on a network share.
Differences Between UEFI and Legacy BIOS
There are several differences between conventional BIOS and UEFI systems and many of them add greater functionality and power to the computer. It also provides a more efficient and secure booting mechanism.
- Larger Address Space: Conventional BIOS were forced to work in a 16-bit mode with a maximum of 1mb addressable space. UEFI allows running in 32- and 64-bit mode allowing larger and more sophisticated programs to be run by the UEFI.
- Support for Larger File Systems: Traditional BIOS only supports the booting of disks that have MBR partitions. MBR partitioning schemes only support 4 partitions per disk and a maximum size of 2TB. UEFI supports the booting of GPT partitions (GUID partitions), which allow the booting of extremely large disks up to 8Zb.
- Improved Security Capabilities: The UEFI specification also improves on the security aspects of the older BIOS systems. It supports several security features such as secure boot. It also has provisions for providing basic cryptographic and public key infrastructure.
- CPU independent design: UEFI has employed a CPU independent design methodology, i.e., it can run on many different types of architectures. The code available is compiled differently for the required platform.
- Powerful Execution Environment: The UEFI specification provides a much more powerful execution environment for computers. It allows special features such as booting over a network, using the mouse, ACPI control and even browsing the web.
- Improved Performance: UEFI-compliant operating systems have been seen to have a significant performance boost not just during the boot process but also during running and powering off the system.
Windows 8 uses UEFI
UEFI, although supported by several operating system vendors for years, has not seen widespread adoption until the release of Windows 8. Windows 8 has tried to incorporate the best parts of UEFI into their latest operating system release particularly the secure boot feature.
One of UEFI's most interesting feature is called Secure Boot; it allows you to boot only an authenticated OS kernel. Windows 8 relies heavily on this method to ensure that only authenticated firmware with a validated kernel image can be booted. This is quite different from older bootstrapping methodologies where any kind of bootloading code can be loaded and executed by the BIOS.
In secure a boot before the BIOS gives full control to the OS, bootloader makes sure that the firmware has been signed. This is done with the help of cryptographic signatures that are embedded on the firmware by the OEM. During the boot process the firmware will compare the platform key with the key present in the firmware of each device. This comparison is carried out between a database of authenticated valid keys; if the key is allowed then the firmware is allowed to execute, otherwise it is rejected.
This allows only authenticated devices to be loaded and ensures that malicious bootloader code is not loaded and executed. The safe boot mechanism in Windows 8 significantly reduces the chances of boot sector viruses and bootkits from launching and affecting the boot process of the machine.
UEFI Boot Process
The UEFI boot process is much like the boot process in conventional BIOS with a few minor changes. The process is divided into stages that take place sequentially and ends with the complete handover of control to the operating system. UEFI booting runs in a 32-bit or 64-bit protected mode on the CPU, not in a 16-bit mode, unlike legacy BIOS.
UEFI also starts with a small amount of code that begins the execution of the entire booting process. This phase is called the security phase (SEC) and it acts as the core root of trust. This is followed by the Pre-EFI initialization (PEI). This mode is similar to the Legacy bios pre-boot initialization phase in which device firmware is checked before boot. Then the driver execution environment is started where the actual initialization of extra device drivers takes place; devices such as network cards and graphic cards are checked in this phase.
The boot device is selected during the BDS (Boot Device Selection) phase. This then transfers control to the bootloader that is located in a GPT partition; the bootloader handles the loading of the OS kernel into memory.
Common BIOS Threats
BIOS is always written to a non-volatile storage device such as an EEPROM which allows the content of the ROM to be overwritten to introduce bug fixes and updates for the particular BIOS version. However this also has great potential for misuse such that malicious programs may also have the ability to modify the contents of the ROM disk if given enough access.
User Initiated Attack
This type of attack is carried out by an end user who uses an unauthenticated file to update the BIOS.. This can be carried out by an end user who doesn't have prior knowledge about the update file or a user with malicious intent.
Malware attacks can be used to exploit vulnerability in bios. The attacker opens a backdoor to the system and cause a BIOS. crash using a vulnerable update version of BIOS.
Network Based or Organizational Attack
This is a large scale and crucial attack on an organizational basis. An attacker who gets access to a compromised update server can carry out an organizational wide attack and infect all systems by rolling out all authorized BIOS. versions to malicious ones.
How Do We Mitigate Common BIOS Threats
This section describes the security measures that an organization should implement in order to secure the BIOS. Since vulnerability in BIOS is crucial point to a system, it is important that every organization should follow predefined guidelines to secure the BIOS structure. The following method can be implemented in an enterprise structure to enhance BIOS security
In order to overcome the malicious attacks on BIOS, we can implement following methods:
- Digital Authentication Method
- Rollback Prevention Method
- Physical Authentication Method
Automated Authentication Method
In this method, the authenticity of BIOS can be ensured through digital signatures. Here BIOS updates should only be installed if its authenticity is verified. Here digital signature embedded update images by BIOS manufactures will be the last level of authorization. This process can be automated by using a signature verification algorithm that ensures the validity of the digital signatures. This digital authentication method must be integrated by providing strong security features.
Rollback Prevention Method
Implement a mechanism that ensures the update images of BIOS so that it will not be rolled back to previous versions. This method ensures that if an update image is to be installed, it should be ensured that its version number is greater than the current one. This can ensure that the b BIOS version is not roll backed to a previous image that contains vulnerability.
In some cases if the current higher version has to be rolled back to a previous lesser version, i.e., if the current updated version of the BIOS contains vulnerability and there are no higher version updates to be installed and the earlier lesser version is stable than the current one. In this case the corresponding authority has to ensure that the lesser version does not contain any vulnerability.
Physical Authentication Method
This method provides the authenticity of updated images by ensuring the physical presence of the corresponding authority (system administrator). Here the authorities can verify the update images and update the BIOS, if the image is a valid one. This method can be used as a subsidiary to digital authentication method by providing as a recovery mechanism in situations like bios crash.
Cloud is not a commodity. And no matter what you call it, computing doesn’t come out of the sky. It comes from physical hardware inside brick and mortar facilities connected by hundreds of miles of networking cable. And no two clouds are built the same way. SoftLayer gives you the highest performing cloud infrastructure available. One platform that takes data centers around the world that are full of the widest range of cloud computing options, and then integrates and automates everything. Join SoftLayer on June 9 at 16th Cloud Expo to learn about IBM Cloud's SoftLayer platform, explore se...
Mar. 28, 2015 02:00 PM EDT Reads: 1,543
The WebRTC Summit 2014 New York, to be held June 9-11, 2015, at the Javits Center in New York, NY, announces that its Call for Papers is open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 16th International Cloud Expo, @ThingsExpo, Big Data Expo, and DevOps Summit.
Mar. 28, 2015 01:00 PM EDT Reads: 1,421
@ThingsExpo has been named the Top 5 Most Influential M2M Brand by Onalytica in the ‘Machine to Machine: Top 100 Influencers and Brands.' Onalytica analyzed the online debate on M2M by looking at over 85,000 tweets to provide the most influential individuals and brands that drive the discussion. According to Onalytica the "analysis showed a very engaged community with a lot of interactive tweets. The M2M discussion seems to be more fragmented and driven by some of the major brands present in the M2M space. This really allows some room for influential individuals to create more high value inter...
Mar. 28, 2015 12:45 PM EDT Reads: 4,591
Wearable technology was dominant at this year’s International Consumer Electronics Show (CES) , and MWC was no exception to this trend. New versions of favorites, such as the Samsung Gear (three new products were released: the Gear 2, the Gear 2 Neo and the Gear Fit), shared the limelight with new wearables like Pebble Time Steel (the new premium version of the company’s previously released smartwatch) and the LG Watch Urbane. The most dramatic difference at MWC was an emphasis on presenting wearables as fashion accessories and moving away from the original clunky technology associated with t...
Mar. 28, 2015 12:00 PM EDT Reads: 1,191
The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Follow new article posts on Twitter at @MicroservicesE
Mar. 28, 2015 12:00 PM EDT Reads: 1,360
SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Raspberry Pi, BeagleBone, Spark and Intel Edison. You will also get an overview of cloud technologies s...
Mar. 28, 2015 11:00 AM EDT Reads: 2,008
SYS-CON Events announced today that SafeLogic has been named “Bag Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. SafeLogic provides security products for applications in mobile and server/appliance environments. SafeLogic’s flagship product CryptoComply is a FIPS 140-2 validated cryptographic engine designed to secure data on servers, workstations, appliances, mobile devices, and in the Cloud.
Mar. 28, 2015 11:00 AM EDT Reads: 1,356
Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch of Docker's initial release in March of 2013, interest was revved up several notches. Then late last...
Mar. 28, 2015 09:15 AM EDT Reads: 2,159
SOA Software has changed its name to Akana. With roots in Web Services and SOA Governance, Akana has established itself as a leader in API Management and is expanding into cloud integration as an alternative to the traditional heavyweight enterprise service bus (ESB). The company recently announced that it achieved more than 90% year-over-year growth. As Akana, the company now addresses the evolution and diversification of SOA, unifying security, management, and DevOps across SOA, APIs, microservices, and more.
Mar. 28, 2015 08:30 AM EDT Reads: 2,000
After making a doctor’s appointment via your mobile device, you receive a calendar invite. The day of your appointment, you get a reminder with the doctor’s location and contact information. As you enter the doctor’s exam room, the medical team is equipped with the latest tablet containing your medical history – he or she makes real time updates to your medical file. At the end of your visit, you receive an electronic prescription to your preferred pharmacy and can schedule your next appointment.
Mar. 28, 2015 08:00 AM EDT Reads: 570
The Open Compute Project is a collective effort by Facebook and a number of players in the datacenter industry to bring lessons learned from the social media giant's giant IT deployment to the rest of the world. Datacenters account for 3% of global electricity consumption – about the same as all of Switzerland or the Czech Republic -- according to people I met at the recent Open Compute Summit in San Jose. With increasing mobility at the edge of the cloud and vast new dataflows being predicted with the growth of the Internet of Things (and The Coming Age of Many Zettabytes) in the near...
Mar. 28, 2015 01:00 AM EDT Reads: 1,782
GENBAND has announced that SageNet is leveraging the Nuvia platform to deliver Unified Communications as a Service (UCaaS) to its large base of retail and enterprise customers. Nuvia’s cloud-based solution provides SageNet’s customers with a full suite of business communications and collaboration tools. Two large national SageNet retail customers have recently signed up to deploy the Nuvia platform and the company will continue to sell the service to new and existing customers. Nuvia’s capabilities include HD voice, video, multimedia messaging, mobility, conferencing, Web collaboration, deskt...
Mar. 28, 2015 01:00 AM EDT Reads: 1,400
The list of ‘new paradigm’ technologies that now surrounds us appears to be at an all time high. From cloud computing and Big Data analytics to Bring Your Own Device (BYOD) and the Internet of Things (IoT), today we have to deal with what the industry likes to call ‘paradigm shifts’ at every level of IT. This is disruption; of course, we understand that – change is almost always disruptive.
Mar. 27, 2015 08:15 PM EDT Reads: 1,009
SYS-CON Events announced today that Cisco, the worldwide leader in IT that transforms how people connect, communicate and collaborate, has been named “Gold Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Cisco makes amazing things happen by connecting the unconnected. Cisco has shaped the future of the Internet by becoming the worldwide leader in transforming how people connect, communicate and collaborate. Cisco and our partners are building the platform for the Internet of Everything by connecting the...
Mar. 27, 2015 07:00 PM EDT Reads: 5,128
SYS-CON Events announced today that robomq.io will exhibit at SYS-CON's @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. robomq.io is an interoperable and composable platform that connects any device to any application. It helps systems integrators and the solution providers build new and innovative products and service for industries requiring monitoring or intelligence from devices and sensors.
Mar. 27, 2015 06:00 PM EDT Reads: 1,357
SYS-CON Media announced today that @WebRTCSummit Blog, the largest WebRTC resource in the world, has been launched. @WebRTCSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. @WebRTCSummit Blog can be bookmarked ▸ Here @WebRTCSummit conference site can be bookmarked ▸ Here
Mar. 27, 2015 06:00 PM EDT Reads: 1,678
Temasys has announced senior management additions to its team. Joining are David Holloway as Vice President of Commercial and Nadine Yap as Vice President of Product. Over the past 12 months Temasys has doubled in size as it adds new customers and expands the development of its Skylink platform. Skylink leads the charge to move WebRTC, traditionally seen as a desktop, browser based technology, to become a ubiquitous web communications technology on web and mobile, as well as Internet of Things compatible devices.
Mar. 27, 2015 06:00 PM EDT Reads: 1,725
Docker is an excellent platform for organizations interested in running microservices. It offers portability and consistency between development and production environments, quick provisioning times, and a simple way to isolate services. In his session at DevOps Summit at 16th Cloud Expo, Shannon Williams, co-founder of Rancher Labs, will walk through these and other benefits of using Docker to run microservices, and provide an overview of RancherOS, a minimalist distribution of Linux designed expressly to run Docker. He will also discuss Rancher, an orchestration and service discovery platf...
Mar. 27, 2015 04:15 PM EDT Reads: 2,369
Sonus Networks introduced the Sonus WebRTC Services Solution, a virtualized Web Real-Time Communications (WebRTC) offer, purpose-built for the Cloud. The WebRTC Services Solution provides signaling from WebRTC-to-WebRTC applications and interworking from WebRTC-to-Session Initiation Protocol (SIP), delivering advanced real-time communications capabilities on mobile applications and on websites, which are accessible via a browser.
Mar. 27, 2015 04:00 PM EDT Reads: 1,682
SYS-CON Events announced today that Aria Systems, the leading innovator in recurring revenue, has been named “Bronze Sponsor” of SYS-CON's @ThingsExpo, which will take place on June 9–11, 2015, at the Javits Center in New York, NY. Proven by the world’s most demanding enterprises, including AAA NCNU, Constant Contact, Falck, Hootsuite, Pitney Bowes, Telekom Denmark, and VMware, Aria helps enterprises grow their recurring revenue businesses. With Aria’s end-to-end active monetization platform, global brands can get to market faster with a wider variety of products and services, while maximizin...
Mar. 27, 2015 04:00 PM EDT Reads: 1,524