type: attack-pattern
spec_version: 2.1
id: attack-pattern--1b7b1806-7746-41a1-a35d-e48dae25ddba
created: 2019-12-19T21:05:38.123Z
created_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
revoked: no
external_references: source_name: mitre-attack
url: https://attack.mitre.org/techniques/T1542/003
external_id: T1542.003
source_name: Lau 2011
description: Lau, H. (2011, August 8). Are MBR Infections Back in Fashion? (Infographic). Retrieved November 13, 2014.
url: http://www.symantec.com/connect/blogs/are-mbr-infections-back-fashion
source_name: Mandiant M Trends 2016
description: Mandiant. (2016, February 25). Mandiant M-Trends 2016. Retrieved November 17, 2024.
url: https://web.archive.org/web/20211024160454/https://www.fireeye.com/content/dam/fireeye-www/current-threats/pdfs/rpt-mtrends-2016.pdf
source_name: welivesecurity
description: Martin Smolár. (2023, March 1). BlackLotus UEFI bootkit: Myth confirmed. Retrieved February 11, 2025.
url: https://www.welivesecurity.com/2023/03/01/blacklotus-uefi-bootkit-myth-confirmed/
source_name: Microsoft Security
description: Microsoft Incident Response. (2023, April 11). Guidance for investigating attacks using CVE-2022-21894: The BlackLotus campaign. Retrieved February 12, 2025.
url: https://www.microsoft.com/en-us/security/blog/2023/04/11/guidance-for-investigating-attacks-using-cve-2022-21894-the-blacklotus-campaign/
object_marking_refs: marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168
modified: 2025-10-24T17:48:28.341Z
name: Bootkit
description: Adversaries may use bootkits to persist on systems. A bootkit is a malware variant that modifies the boot sectors of a hard drive, allowing malicious code to execute before a computer's operating system has loaded. Bootkits reside at a layer below the operating system and may make it difficult to perform full remediation unless an organization suspects one was used and can act accordingly.

In BIOS systems, a bootkit may modify the Master Boot Record (MBR) and/or Volume Boot Record (VBR).(Citation: Mandiant M Trends 2016) The MBR is the section of disk that is first loaded after completing hardware initialization by the BIOS. It is the location of the boot loader. An adversary who has raw access to the boot drive may overwrite this area, diverting execution during startup from the normal boot loader to adversary code.(Citation: Lau 2011)

The MBR passes control of the boot process to the VBR. Similar to the case of MBR, an adversary who has raw access to the boot drive may overwrite the VBR to divert execution during startup to adversary code.

In UEFI (Unified Extensible Firmware Interface) systems, a bootkit may instead create or modify files in the EFI system partition (ESP). The ESP is a partition on data storage used by devices containing UEFI that allows the system to boot the OS and other utilities used by the system. An adversary can use the newly created or patched files in the ESP to run malicious kernel code.(Citation: Microsoft Security)(Citation: welivesecurity)
kill_chain_phases: kill_chain_name: mitre-attack
phase_name: persistence
kill_chain_name: mitre-attack
phase_name: defense-evasion
x_mitre_attack_spec_version: 3.2.0
x_mitre_deprecated: no
x_mitre_domains: enterprise-attack
x_mitre_is_subtechnique: yes
x_mitre_modified_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
x_mitre_platforms: Linux
Windows
x_mitre_version: 1.2