type: x-mitre-data-component
spec_version: 2.1
id: x-mitre-data-component--b9d031bb-d150-4fc6-8025-688201bf3ffd
created: 2021-10-20T15:05:19.271Z
created_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
revoked: no
external_references: source_name: mitre-attack
url: https://attack.mitre.org/datacomponents/DC0004
external_id: DC0004
object_marking_refs: marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168
modified: 2025-10-21T15:14:38.020Z
name: Firmware Modification
description: Changes made to firmware, which may include its settings, configurations, or underlying data. This can encompass alterations to the Master Boot Record (MBR), Volume Boot Record (VBR), or other firmware components critical to system boot and functionality. Such modifications are often indicators of adversary activity, including malware persistence and system compromise. Examples: 

- Changes to Master Boot Record (MBR): Modifying the MBR to load malicious code during the boot process.
- Changes to Volume Boot Record (VBR): Altering the VBR to redirect boot processes to malicious locations.
- Firmware Configuration Changes: Modifying BIOS/UEFI settings such as disabling Secure Boot.
- Firmware Image Tampering: Updating firmware with a malicious or unauthorized image.
- Logs or Errors Indicating Firmware Changes: Logs showing unauthorized firmware updates or checksum mismatches.

This data component can be collected through the following measures:

- BIOS/UEFI Logs: Enable and monitor BIOS/UEFI logs to capture settings changes or firmware updates.
- Firmware Integrity Monitoring: Use tools or firmware security features to detect changes to firmware components.
- Endpoint Detection and Response (EDR) Solutions: Many EDR platforms can detect abnormal firmware activity, such as changes to MBR/VBR or unauthorized firmware updates.
- File System Monitoring: Monitor changes to MBR/VBR-related files using tools like Sysmon or auditd.
 - Windows Example (Sysmon): Monitor Event ID 7 (Raw disk access).
 - Linux Example (auditd): `auditctl -w /dev/sda -p wa -k firmware_modification`
- Network Traffic Analysis: Capture firmware updates downloaded over the network, particularly from untrusted sources. Use network monitoring tools like Zeek or Wireshark to analyze firmware-related traffic.
- Secure Boot Logs: Collect and analyze Secure Boot logs for signs of tampering or unauthorized configurations. Example: Use PowerShell to retrieve Secure Boot settings on Windows: `Confirm-SecureBootUEFI`
- Vendor-Specific Firmware Tools: Many hardware vendors provide tools for firmware integrity checks.Examples:
 - Intel Platform Firmware Resilience (PFR).
 - Lenovo UEFI diagnostics.
x_mitre_modified_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
x_mitre_deprecated: no
x_mitre_domains: ics-attack
enterprise-attack
x_mitre_version: 2.0
x_mitre_attack_spec_version: 3.3.0
x_mitre_log_sources: name: Firmware
channel: None
name: networkdevice:syslog
channel: Image Upgrade / Configuration Change
name: networkdevice:config
channel: Boot image path or firmware configuration variable modified outside of maintenance windows
name: WinEventLog:Microsoft-Windows-Kernel-Boot
channel: Firmware integrity validation failed or boot configuration tampered
name: auditd:SYSCALL
channel: write access to /dev/mem or /sys/firmware/efi/efivars
name: macos:unifiedlog
channel: boot failure events or SMC validation errors
name: networkdevice:firmware
channel: Firmware update initiated or bootloader tampering detected
name: networkdevice:config
channel: Log entries indicating ROMMON image upgrade commands (boot system, upgrade rom-monitor)
name: networkdevice:config
channel: Boot variable modified to point to non-standard or unsigned image
name: firmware:integrity 
channel: Firmware integrity verification failures or mismatches against expected UEFI/firmware image baselines
name: auditd:SYSCALL
channel: ioctl/write: Direct firmware update or device memory manipulation syscalls
name: firmware:smart
channel: Unexpected firmware-level errors or abnormal S.M.A.R.T. log entries
name: macos:unifiedlog
channel: Firmware update events or kernel extension (kext) loads not signed by Apple
name: firmware:integrity
channel: Baseline mismatch or unexpected EFI module detected during integrity checks
name: macos:osquery
channel: Unexpected changes in EFI or NVRAM variables controlling hardware boot state
name: networkdevice:syslog
channel: Custom firmware or routing changes
name: etw:Microsoft-Windows-Kernel-Storage
channel: Raw disk I/O operations bypassing NTFS APIs
name: firmware:runtime
channel: Debug or memory access commands indicating attempts to alter OS instructions in memory
name: networkdevice:syslog
channel: Boot information log showing image loaded from TFTP server instead of local storage