An insider attack is one of the biggest threats faced by modern enterprises, where even a good working culture might not be sufficient to prevent it. Companies implement sophisticated technology to monitor their employees but it’s not always easy for them to distinguish between an insider and an outside attack.
Those who target and plan attacks from the outside might create strategies for obtaining insider knowledge and access by either resorting to an existing employee, or by making one of their own an insider.
They may introduce a problem to both individuals (in the form of financial fraud, for example) and companies (by abusing authorization credentials provided to legitimate employees). In this scenario, a victim and an attacker are sharing physical space, which makes it very easy to gain login and other sensitive information.
According to CERT, a malicious insider is; a current or former employee, contractor, or business partner who has or had authorised access to an organisation’s network system or data and intentionally exceeded or misused that access in a manner that negatively affected the confidentiality, integrity, or availability of the organisation’s information. Furthermore, CERT split insider crimes into three categories:
- Insider IT Sabotage, where IT is used to direct specific harm at an organisation or an individual.
- Insider Theft of Intellectual Property is the use of IT to steal proprietary information from an organisation.
- Insider Fraud uses IT to add, modify and/or delete an organisation’s data in an unauthorised manner for personal gain. It also includes the theft of information needed for identity crime.
But how can companies detect and prevent such attacks?
In his paper, Framework for Understanding and Predicting Insider Attacks, Eugene Schultz suggests that insiders make human errors, which when spotted can help in preventing such threats. Therefore, constant monitoring, especially focused on low-level employees, is one of the basic measures for preventing insider attacks and gathering evidence.
There are a number of precursors of insider attacks that can help to identify and prevent them:
- Deliberate markers – These are signs which attackers leave intentionally. They can be very obvious or very subtle, but they all aim to make a statement. Being able to identify the smaller, less obvious markers can help prevent the “big attack.”
- Meaningful errors – Skilled attackers tend to try and cover their tracks by deleting log files but error logs are often overlooked.
- Preparatory behaviour – Collecting information, such as testing countermeasures or permissions, is the starting point of any social engineering attack.
- Correlated usage patterns – It is worthwhile to invest in investigating the patterns of computer usage across different systems. This can reveal a systematic attempt to collect information or test boundaries.
- Verbal behaviour – Collecting information or voicing dissatisfaction about the current working conditions may be considered one of the precursors of an insider attack.
- Personality traits – A history of rule violation, drug or alcohol addiction, or inappropriate social skills may contribute to the propensity of committing an insider attack.
There are a number of insider attackers who are merely pawns for another inside or outside mastermind. He or she is usually persuaded or trained to perpetrate or facilitate the attack, alone or in collusion with other (outside) agents, motivated by the expectation of personal gain.
Organisations may unknowingly make themselves vulnerable to insider attacks by not screening newcomers properly in the recruitment, not performing threat analyses, or failing to monitor their company thoroughly. Perhaps the most important thing they overlook is to keep everybody’s morale high by communicating to employees that they are valued and trusted.