BIOS Rootkit

Definition of BIOS Rootkit

A BIOS rootkit is a malicious software that targets the Basic Input/Output System (BIOS) of a computer, allowing the attacker to maintain persistent control over the infected device. It runs at a lower level than traditional rootkits, making it difficult to detect and remove. Its stealth capabilities enable it to intercept and manipulate the operating system’s behavior while avoiding antivirus and security software.


B-I-O-S rootkit in phonetics is:B = /biː/I = /aɪ/O = /oʊ/S = /ɛs/Rootkit = /ˈruːtˌkɪt/So, the phonetic pronunciation of “BIOS rootkit” is /biː-aɪ-oʊ-ɛsˈ ˈruːtˌkɪt/.

Key Takeaways

  1. BIOS Rootkits are stealthy malware that infect the BIOS of a computer, making them nearly undetectable by standard anti-malware tools and allowing the attacker to gain persistent access to the system.
  2. They can survive operating system reinstalls or hard drive replacements as they are stored at the BIOS level, making them difficult to remove and increasing their potential for damage.
  3. Preventing BIOS Rootkit infections requires keeping the BIOS firmware up-to-date, enabling BIOS security features such as password protection, and performing regular system checks with specialized tools that can detect BIOS-level malware.

Importance of BIOS Rootkit

The term BIOS Rootkit is important because it refers to a particularly malicious type of software that targets the BIOS (Basic Input/Output System) of a computer, offering an attacker extensive control over the compromised system.

By infecting the BIOS – a fundamental component of a computer that manages hardware, system settings, and the boot process – a BIOS Rootkit can persist undetected since it operates at a lower level than traditional antivirus software.

This means it can survive operating system reinstallation and hard drive replacement, rendering it extremely difficult to remove.

Consequently, BIOS Rootkits serve as a significant threat to computer security and data safety, highlighting the importance of ongoing research and development focused on better detection and prevention technologies.


A BIOS rootkit is a malicious software designed to infiltrate and embed itself deep within the firmware of a computer’s Basic Input/Output System (BIOS). Utilized by cybercriminals, its primary purpose is to grant unauthorized access and control of the affected system while remaining undetected by conventional antivirus or security programs. This level of persistence enables attackers to execute various operations, such as data theft, espionage, or system sabotage, all while avoiding removal by standard security measures.

One advantage of a BIOS rootkit is its ability to survive system reboots and operating system reinstalls, making it incredibly difficult to eliminate. Upon compromising a system, the rootkit’s code is executed during the boot process, preceding the operating system (OS), and therefore remains active even if the system’s disk is entirely wiped and a new OS installed.

Nevertheless, adversaries that employ BIOS rootkits can wreak havoc on targeted systems, potentially causing data loss or extensive damage. Due to this, cybersecurity experts place a strong emphasis on devising and implementing mitigation strategies to counter these powerful threats in the ever-evolving landscape of digital security.

Examples of BIOS Rootkit

A BIOS rootkit is a malware program that infects the low-level system firmware, such as a computer’s BIOS (Basic Input/Output System). It is challenging to detect and remove because it operates at a deeper level than typical operating system malware. Here are three real-world examples of BIOS rootkits that emerged in the past:

Mebromi: Also referred to as Trojan.Bioskit, Mebromi was discovered in 2011 and was the first known BIOS rootkit in the wild, mainly targeting users in China. Mebromi could infect the Windows operating system and write its payload to the BIOS, making it difficult to detect and remove by traditional antivirus methods. The rootkit would reinstall itself every time Windows booted up, even if the infected hard drive was replaced or the operating system was reinstalled.

Hacking Team UEFI Rootkit: In 2015, the leaked data from Italian surveillance software company Hacking Team revealed that they had developed a BIOS rootkit that targeted UEFI (Unified Extensible Firmware Interface) firmware. This rootkit allowed them to compromise target systems persistently and perform covert surveillance activities, such as keystroke monitoring, taking screenshots, and exfiltrating files. By targeting UEFI, the rootkit would remain active even if the user formatted the hard drive or replaced it with a new one.

LoJax: LoJax, discovered in 2018, was a UEFI-based rootkit attributed to the Russian APT (Advanced Persistent Threat) group known as APT28 or Fancy Bear. LoJax was primarily used for cyber-espionage and persistence in the target systems. It involved the abuse of legitimate system management tools, like LoJack, to rewrite the system’s UEFI module, making it difficult for antivirus and endpoint detection software to identify and eradicate it.

FAQ: BIOS Rootkit

What is a BIOS Rootkit?

A BIOS rootkit is a malicious software that infects the BIOS (Basic Input/Output System) of a computer, making it extremely persistent and difficult to remove. This type of rootkit allows the attacker to maintain control over the infected system even after the operating system has been reinstalled or the hard drive has been wiped.

How does a BIOS Rootkit work?

A BIOS rootkit works by injecting malicious code into the BIOS firmware, which is typically stored on an EEPROM or flash memory chip on the computer’s motherboard. This code is executed during the startup process of the computer, before the operating system loads. By infecting the BIOS, the rootkit can remain hidden from antivirus applications and other security measures running on the operating system.

How can I detect a BIOS Rootkit?

Detecting a BIOS rootkit can be challenging due to its deep level of system integration. Some methods to detect a BIOS rootkit include using specialized hardware-based security tools, inspecting the BIOS manually using BIOS analysis tools, or comparing your current BIOS setup with a known-clean version.

How can I protect my computer from BIOS Rootkits?

There are several steps you can take to protect your computer from BIOS rootkits:

  1. Keep your BIOS updated to the latest version.
  2. Enable BIOS security features such as password protection, secure boot, and hardware-based security modules like TPM (Trusted Platform Module).
  3. Use a robust antivirus program and keep it updated with the latest definitions.
  4. Practice good online safety habits, like avoiding clicking on suspicious links and not downloading software from untrusted sources.

How can I remove a BIOS Rootkit?

Removing a BIOS rootkit can be difficult and may require advanced technical skills. Some potential methods for removing BIOS rootkits include reflashing the BIOS with clean firmware, using specialized BIOS rootkit removal tools, or physically replacing the infected EEPROM or flash memory chip. Because the process is complicated, it is advisable to seek professional help if you suspect a BIOS rootkit infection.

Related Technology Terms

  • Firmware malware
  • UEFI rootkit
  • System-level persistence
  • Bootkit
  • Hardware-based security

Sources for More Information


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