An insider threat is a malicious threat to an organization that comes from people within the organization, such as employees, former employees, contractors or business associates, who have inside information concerning the organization's security practices, data and computer systems. The threat may involve fraud, the theft of confidential or commercially valuable information, the theft of intellectual property, or the sabotage of computer systems. The insider threat comes in three categories:
- Malicious insiders, which are people who take advantage of their access to inflict harm on an organization;
- Negligent insiders, which are people who make errors and disregard policies, which place their organizations at risk; and
- Infiltrators, who are external actors that obtain legitimate access credentials without authorization.
Insiders may have accounts giving them legitimate access to computer systems, with this access originally having been given to them to serve in the performance of their duties; these permissions could be abused to harm the organization. Insiders are often familiar with the organization's data and intellectual property as well as the methods that are in place to protect them. This makes it easier for the insider to circumvent any security controls of which they are aware. Physical proximity to data means that the insider does not need to hack into the organizational network through the outer perimeter by traversing firewalls; rather they are in the building already, often with direct access to the organization's internal network. Insider threats are harder to defend against than attacks from outsiders, since the insider already has legitimate access to the organization's information and assets.
An insider may attempt to steal property or information for personal gain, or to benefit another organization or country. The threat to the organization could also be through malicious software left running on its computer systems by former employees, a so-called Logic bomb.
Insider threat is an active area of research in academia and government.
The CERT Coordination Center at Carnegie-Mellon University maintains the CERT Insider Threat Center, which includes a database of more than 850 cases of insider threats, including instances of fraud, theft and sabotage; the database is used for research and analysis. CERT's Insider Threat Team also maintains an informational blog to help organizations and businesses defend themselves against insider crime.
In a 2018 insider threat report whitepaper, it was determined that 53% of companies surveyed had confirmed insider attacks against their organization in the previous 12 months, with 27% saying insider attacks have become more frequent.
A report published in July 2012 on the insider threat in the U.S. financial sector gives some statistics on insider threat incidents: 80% of the malicious acts were committed at work during working hours; 81% of the perpetrators planned their actions beforehand; 33% of the perpetrators were described as "difficult" and 17% as being "disgruntled". The insider was identified in 74% of cases. Financial gain was a motive in 81% of cases, revenge in 23% of cases, and 27% of the people carrying out malicious acts were in financial difficulties at the time.
The US Department of Defense Personnel Security Research Center published a report that describes approaches for detecting insider threats. Earlier it published ten case studies of insider attacks by information technology professionals.
- "FBI Counterintelligence: The Insider Threat. An introduction to detecting and deterring an insider spy". Fbi.gov. Archived from the original on 2014-02-10. Retrieved 2014-03-08.
- "The CERT Insider Threat Center". Cert.org. Retrieved 2014-03-08.
- "Insider Threat Blog". CERT. Retrieved 10 August 2012.
- "Insider Threat 2018 Report". Cybersecurity Insiders. Retrieved 2018-12-13.
- Cummings, Adam; Lewellen, Todd; McIntire, David; Moore, Andrew; Trzeciak, Randall (2012), Insider Threat Study: Illicit Cyber Activity Involving Fraud in the U.S. Financial Services Sector, Software Engineering Institute, Carnegie Mellon University, (CMU/SEI-2012-SR-004)
- Shaw, Eric; Fischer, Lynn; Rose, Andrée (2009), Insider Risk Evaluation and Audit (PDF), Department of Defense Personnel Security Research Center, TR 09-02
- Shaw, Eric; Fischer, Lynn (2005), Ten Tales of Betrayal: The Threat to Corporate Infrastructures by Information Technology Insiders Analysis and Observations (PDF)