facility, or operation can be manifest. Categorize and classify threats as follows: Categories Classes Human Intentional Unintentional Environmental Natural Fabricated 2. Any circumstance or event with the potential to cause harm to a system in the form of destruction, disclosure, modification or data, and/or denial of service. 3. Any circumstance or event with the potential to cause harm to the ADP system or activity in the form of destruction, disclosure, and modification of data, or denial of service. A threat is a potential for harm. The presence of a threat does not mean that it will necessarily cause actual harm. Threats exist because of the very existence of the system or activity and not because of any specific weakness. For example, the threat of fire exists at all facilities regardless of the amount of fire protection available. 4. Types of computer systems related adverse events (i. e. , perils) that may result in losses. Examples are flooding, sabotage and fraud. 5. An assertion primarily concerning entities of the external environment (agents); we say that an agent (or class of agents) poses a threat to one or more assets; we write: T(e;i) where: e is an external entity; i is an internal entity or an empty set. 6. An undesirable occurrence that might be anticipated but is not the result of a conscious act or decision. In threat analysis, a threat is defined as an ordered pair, <peril; asset category>, suggesting the nature of these occurrences but not the details (details are specific to events). 7. The potential violation of security. 8. A set of properties of a specific external entity (which may be either an individual or class of entities) that, in union with a set of properties of a specific internal entity, implies a risk (according to a body of knowledge).g Phenomenology The term "threat" relates to some other basic security terms as shown in the following diagram: + - - - - - - - - - - - - + + - - - - + + - - - - - - - - - - -+ | An Attack: | |Counter- | | A System Resource: | | i.e., A Threat Action | | measure | | Target of the Attack | | +----------+ | | | | +-----------------+ | | | Attacker |<==================||<========= | | | | i.e., | Passive | | | |