An approach is provided for determining a likelihood of an attack on a first computer system of a first business. Characteristics of the first business and a second business are determined. The second business has a second computer system currently or recently under attack. The characteristics include respective industries, sizes, geographical locations, types of sensitive data, and security vulnerabilities associated with the first and second businesses or first and second computer systems, an address of traffic through a device in the first computer system, and an address of an entity responsible for the attack on the second computer system. Based on a similarity between the characteristics of the first and second businesses, a likelihood that the entity responsible for the attack on the second computer system will attack the first computer system of the first business is determined.