In computer security a countermeasure is an action, device, procedure, or technique that reduces a threat, vulnerability, or attack, eliminating or preventing it by minimizing the harm it can cause.
[2][4] In telecommunications, communication countermeasures are defined as security services as part of the OSI Reference model by ITU-T X.800 Recommendation.
The attack can be active when it attempts to alter system resources or affect their operation: so it compromises integrity or availability.
[4] If a potential malicious actor has physical access to a computer system, they have a greater chance of inflicting harm upon it.
[8] In an unsecured scenario, a malicious actor may steal or destroy storage devices such as hard drives or SSDs, resulting in the destruction or theft of valuable data.
If this device is a boot drive, however, it must be unencrypted in a pre-boot environment so the operating system can be accessed.