Disruption

Disruption is any attack that prevents an organisation from operating normally. The attacker's aim is not mainly to steal information: it is to stop services working or to make the organisation's data unreliable.

Disruption usually shows itself in one of two ways. A service can be made unavailable, or stored information can be altered so that staff can no longer trust it.

• An attacker repeatedly enters wrong passwords for a tennis club's court-booking site, so members' accounts lock and they cannot book a court for the whole weekend.
• Someone edits the stock figures for a bike shop so the system claims 40 helmets are in the warehouse when only 4 are there. Staff order the wrong amounts and customers are let down at the counter.

Targets and reasons

Disruption is a reason in its own right: the attacker wants to stop the organisation working, not to steal from it. The target does not have to be a business. A college, a health clinic, government services and political groups can all be disrupted in the same way, because each relies on systems that must keep working.

Disruption can hit organisations of every size. A small charity and a supermarket chain can both be disrupted: their systems simply stop being usable.

What it costs the organisation

Loss of earnings comes first. If a café chain's payment terminals are down for a whole afternoon, customers who cannot pay tend to leave, and some never return. Reputation is the second cost. A service that keeps failing looks careless, so customers may move to a competitor and may not trust that organisation with their details again.