Defining Moving Target Defence (MTD)
Moving Target Defence (MTD) is a cybersecurity strategy that aims to enhance the security of systems and networks by continuously changing their attack surface and making them more challenging to target and exploit by cybercriminals. MTD operates on the principle that increasing the uncertainty and complexity for attackers reduces the likelihood of successful attacks and minimises the potential damage.
At its core, MTD seeks to disrupt attackers’ advantage by shifting the security landscape. Traditional cybersecurity approaches often focus on static defensive measures like firewalls, intrusion detection systems, and antivirus software. While important, these measures can be circumvented by determined attackers familiar with the security infrastructure and vulnerabilities of the target environment. Conversely, MTD embraces a proactive and dynamic approach that aims to neutralise threats before they can exploit vulnerabilities.
- Increased Attack Complexity: By frequently changing system configurations, network protocols, or other aspects of the environment, MTD introduces a high degree of uncertainty for attackers. This complexity makes it more challenging for attackers to understand and exploit vulnerabilities, as their existing knowledge and attack techniques may need to be revised.
- Reduced Attack Surface: MTD aims to shrink the attack surface available to potential attackers. By constantly altering system parameters and configurations, it becomes more difficult for attackers to locate and exploit vulnerable entry points. This helps to mitigate the impact of known vulnerabilities and reduces the success rate of attacks.
- Improved Threat Detection: MTD incorporates various techniques to detect and respond to potential threats. These techniques include behaviour-based monitoring, anomaly detection, and active defence mechanisms. By continuously analysing system behaviour and comparing it to established patterns, MTD can identify suspicious activities and respond in real time, thus minimising the time window for attackers to exploit vulnerabilities.
- Adaptive Defence: MTD systems can adapt and respond to emerging threats. They can dynamically adjust security measures based on the evolving threat landscape. This adaptability enables organisations to stay ahead of attackers by proactively modifying system configurations, deploying additional security controls, or rerouting network traffic to reduce the impact of attacks.
- Increased Resilience: MTD helps enhance the overall resilience of systems and networks. Organisations can better withstand attacks and recover more quickly by continuously evolving and changing their defence mechanisms. Even if an attacker manages to breach one layer of defence, the constantly changing nature of the environment makes it harder for them to gain a foothold and creep more profoundly into the network.
- Extended Patching Time: One of the challenges in traditional cybersecurity is the timely deployment of patches and updates to fix vulnerabilities. MTD can provide a temporary mitigation measure by frequently changing system configurations, making it harder for attackers to exploit known vulnerabilities while organisations work on deploying patches. This extended patching time can be crucial in critical environments where immediate patch deployment may not be feasible.
- Deception and Misdirection: MTD often employs deception techniques to mislead and confuse attackers. By deploying honeypots, decoy systems, or virtual environments, organisations can lure attackers into a controlled environment, diverting their attention and resources from critical assets. Deception can also help organisations gather intelligence on attacker techniques and motivations.
- Requires Large Incremental Change: MTD will require significant downtime and an outlay of resources to implement into an organisation, and this outage period will significantly expose organisations to attacks. This can be detrimental because there is no failsafe option to protect the organisation during this period – ultimately impacting revenue and business operations.
- Complexity and Resource Allocation: Introducing dynamic and constantly changing elements to an environment can significantly increase complexity. This complexity can be challenging for cybersecurity teams and may require further specialised skills and tools. Additionally, the resource allocation of constantly adapting the system to create moving targets may affect performance and resource utilisation, creating another avenue to alert fatigue.
- Confidence and Business Change: Often, with new technology comes the confidence factor for cybersecurity teams to successfully implement and manage the technology. With MTD, an organisation would need to be able to make this change seamlessly and put security teams in a position to manage it soundly. All this would need to happen without impacting business operations and the reputation of the security team when they want to make changes to the organisation.
- Attacker Adaptation: Just as defenders implement moving target techniques, attackers can also adapt their tactics to exploit the potential vulnerabilities of the technology. This could lead to a back and forth, where attackers develop strategies to counter MTD, necessitating ongoing adjustments, updates and patches to the defence measures cybersecurity teams were unprepared for.
- Compliance and Regulations: Using a technology adapted from military measures can come with a whole host of red tape during implementation. Some industries and regions have strict compliance and regulatory requirements. Implementing MTD may introduce complexities in meeting these requirements, especially if significant steps of change to organisations need to be approved and documented through rigorous processes.
- Vendor Support: If an organisation relies on third-party vendors for their tools, skills, or services, obtaining support for MTD implementations and ensuring synergy can be challenging. There is always the potential that vendors may still need to adapt their products to support MTD strategies fully.
Moving Target Defence offers a proactive and dynamic approach to cybersecurity, leveraging the element of surprise and uncertainty to defend against attackers. By continuously changing system configurations, expanding the attack surface, improving threat detection, adapting to emerging threats, increasing resilience, and deploying deception techniques, MTD can provide organisations with a more robust and effective defence against cyber threats. Still, it may come at a significant cost.
MTD can be a valuable addition to a cybersecurity strategy, but it’s not a one-size-fits-all solution. Its effectiveness depends on a particular use case, the complexity and flexibility of an organisation’s environment, and a considerable outlay from an organisation’s resources and goals. While MTD has the potential to enhance security and protect against certain types of attacks, it should be part of a comprehensive cybersecurity approach that includes other defensive measures and best practices. Should MTD become a more cost-effective approach and require less complexity for installation and resources by providers – this could be a welcome bow to the quiver for cybersecurity as a whole.