event (e.g. power surge caused by lightning) that alters system functions or data. "Obstruction" A threat action that interrupts delivery of system services by hindering system operations. "Interference" Disruption of system operations by blocking communications or user data or control information. "Overload" Hindrance of system operation by placing excess burden on the performance capabilities of a system component. (See: flooding.) "Usurpation" (a threat consequence) A circumstance or event that results in the control of system services or functions by an unauthorized entity. The following threat actions can cause usurpation: "Misappropriation" A threat action whereby an entity assumes unauthorized logical or physical control of a system resource. "Theft of service" Unauthorized use of service by an entity. "Theft of functionality" Unauthorized acquisition of actual hardware, software, or firmware of a system component. "Theft of data" Unauthorized acquisition and use of data. "Misuse" A threat action that causes a system component to perform a function or service that is detrimental to system security. "Tamper" In the context of misuse, deliberate alteration of a system's logic, data, or control information to cause the system to perform unauthorized functions or services. "Malicious logic" In the context of misuse, any hardware, software, or firmware intentionally introduced into a system to perform or control the execution of an unauthorized function or service. "Violation of permissions" Action by an entity that exceeds the entity's system privileges by executing an unauthorized function. Threat landscape or environment A collection of threats in a particular domain or context, with information on identified vulnerable assets, threats, risks, threat actors and observed trends. Threat management Threats should be managed by operating an ISMS, performing all the IT risk management activities foreseen by laws, standards and methodologies. Very large organizations tend to adopt business continuity management plans in order to protect, maintain and recover business-critical processes and systems. Some of these plans foreseen to set up computer security incident response team (CSIRT) or computer emergency response team (CERT) There is some kind of verification of the threat management process: Information security audit Penetration test Most organizations perform a subset of these steps, adopting countermeasures based on a non-systematic approach: computer insecurity studies the battlefield of computer security exploits and defences that results. Information security awareness is a significant market (see :category:Computer security companies). There has been a lot of software developed to deal with IT threats, including both open-source software (see :category:free security