T1495 - Firmware Corruption#
Adversaries may overwrite or corrupt the flash memory contents of system BIOS or other firmware in devices attached to a system in order to render them inoperable or unable to boot, thus denying the availability to use the devices and/or the system.(Citation: Symantec Chernobyl W95.CIH) Firmware is software that is loaded and executed from non-volatile memory on hardware devices in order to initialize and manage device functionality. These devices may include the motherboard, hard drive, or video cards.
In general, adversaries may manipulate, overwrite, or corrupt firmware in order to deny the use of the system or devices. For example, corruption of firmware responsible for loading the operating system for network devices may render the network devices inoperable.(Citation: dhs_threat_to_net_devices)(Citation: cisa_malware_orgs_ukraine) Depending on the device, this attack may also result in Data Destruction.
Atomic Tests:#
Currently, no tests are available for this technique.
Detection#
System firmware manipulation may be detected.(Citation: MITRE Trustworthy Firmware Measurement) Log attempts to read/write to BIOS and compare against known patching behavior.
Shield Active Defense#
System Activity Monitoring#
Collect system activity logs which can reveal adversary activity.
Capturing system logs can show logins, user and system events, etc. Collecting this data and potentially sending it to a centralized location can help reveal the presence of an adversary and the actions they perform on a compromised system.
Opportunity#
There is an opportunity to create a detection with a moderately high probability of success.
Use Case#
A defender can collect system activity and detect commands that interact with firmware. This can speed up the recovery of a system.
Procedures#
Ensure that systems capture and retain common system level activity artifacts that might be produced. Monitor Windows systems for event codes that reflect an adversary changing passwords, adding accounts to groups, etc.