A threat intelligence service (TI service) is a provider of information about current or emerging threats that could negatively impact the security of a customer’s organization.
Threat intelligence services range in cost and complexity from free or low-cost data feeds to high-priced and comprehensive systems that handle data aggregation and correlation to provide organized, analyzed and refined information. Providers at the most expensive end of the scale often also offer consultancy services.
Threat intelligence services evolved as a way to effectively use the massive quantities of data that security organizations have always gathered. The SANS Internet Storm Center and CERT, for example, have long tracked information related to security threats; both organizations make threat intelligence feeds of updated information available free through their websites. Some companies offer threat intelligence feeds that are essentially the same as the freely-available data.
Symantec and other security product providers maintain global threat databases, which are constantly being populated with data gathered by software agents running on millions of client devices. That data, along with feeds from other sources, provides the information that threat intelligence services make available to customers.
However, it takes considerable time, effort and expertise to transform all that data into information that's pertinent to an organization – which is why many businesses opt for more full-service threat intelligence services.
See an introductory tutorial on threat intelligence: