Threats Posed by Attacks

A computer system can be attacked in many ways, and each attack can cause harm in more than one way. An attacker may copy data out and read it, alter records so they no longer match reality, wipe files, or lock data so that the owner cannot get to it. For example, a school's timetable system could be accessed and a room booking changed, so classes are sent to the wrong room all week. The data is still there, but it is no longer trustworthy.

Attacks also harm the services a system provides, by slowing them down or putting them out of action. If a coach company's booking system is out of action, passengers cannot reserve seats, and staff spend the day taking bookings on paper, so the company loses fares while it pays for repairs. The organisation can lose money in other ways too: stolen funds, refunds or compensation, and the cost of replacing equipment and restoring data. Customers who no longer trust the organisation may take their business elsewhere, so reputation matters. If personal data is not protected, the organisation can also face legal action.

Purpose and threat

The purpose of an attack is what the attacker is trying to achieve, such as finding out what will be on next week's science test. The threat is the harm the attack can cause to devices or systems: the test file being opened and copied, the computer holding it being unusable on the day, or the file being wiped altogether. The two are linked but not the same — two attacks might share a purpose but threaten a system in different ways.

Describing and recognising attacks

When you describe an attack, say how it is used and what it is intended to achieve. A good description does not stop at the name. If a scenario gives a method and a purpose, match it to the form of attack that matches both the method and the purpose. For example, if a scenario says a person was talked into revealing something that should have stayed private, the method is deception, and the form of attack that fits is social engineering.