There have been more than 2400 major terrorist attacks in the 10 years since 9/11, and the perpetrators have become more diverse, says Risk Management Solutions (RMS).

The risk modeller says the threat has become dispersed due to the activities of Al-Qaeda and its affiliates among Islamist groups that espouse violence.

The report, Terrorism Risk in the Post-9/11 Era, also has a study of the Norway attack that killed 77 people, which RMS says illustrates the difficulty of preventing “lone wolf” attacks.

It says that while security agencies can infiltrate extremist groups and are more likely to pick up communications between their members, an individual can be hard to detect.

RMS Senior VP Emerging Risk Solutions Peter Ulrich says management of terrorism risk has evolved since 9/11.

The insurance industry has become more comfortable using loss models to manage the risk and insurers are using realistic scenarios to monitor exposure as well as models of probability similar to those used in catastrophe modelling.