The "Assume Breach" pillar of the Zero Trust model is grounded in the understanding that security breaches are not just possible; they are inevitable. This pragmatic approach dictates that organizations should plan and build their security architectures as if the attackers are already inside their network. Here’s a detailed exploration of the critical strategies under this pillar:
1. Detect and Respond
Under the assumption of a breach, detection, and response capabilities are designed to identify and mitigate threats swiftly before they can cause significant damage. This includes:
- Intrusion Detection Systems (IDS): monitor network traffic for suspicious activities and known threats, signaling alerts when potential security breaches are detected.
- Security Information and Event Management (SIEM) Systems: SIEM systems collect and aggregate logs from various sources within the network, applying analytics to detect patterns or anomalies that might indicate malicious activity.
- Automated Response Solutions: Upon detecting a threat, automated systems can respond immediately by isolating affected segments, blocking malicious communications, or terminating harmful processes, thereby reducing the window of opportunity for attackers to exploit.
2. Limit Lateral Movement
Once an attacker gains access to a part of the network, their next goal is often to move laterally to reach valuable data or systems. Strategies to limit this movement include:
- Network Segmentation: Dividing the network into smaller, isolated segments or zones can control how traffic moves across the network and limit access to critical assets. Firewalls and access control lists (ACLs) enforce these boundaries by controlling traffic flow based on security policies.
- Application Segmentation: Beyond network segmentation, application-level segmentation can further restrict access to applications based on user identity and context, limiting an attacker’s ability to access sensitive applications.
- User and Entity Behavior Analytics (UEBA): This technology uses machine learning to understand normal user behavior and can detect deviations that suggest malicious activity, such as an unauthorized attempt to access data.
3. Enhance Monitoring
Comprehensive monitoring is essential for detecting unusual activities that may indicate a breach. Enhanced monitoring techniques include:
- Log Management: Collecting and analyzing logs from all devices and applications across the network provides visibility into activities and potential security incidents.
- Endpoint Detection and Response (EDR): EDR tools are deployed on endpoints to monitor and collect data about potentially malicious activities, which can be used to identify and respond to threats.
Continuous Monitoring: Continuous monitoring involves the ongoing analysis of security controls and user activities, ensuring that any deviations from the norm can be detected and responded to in real-time.
The "Assume Breach" approach shifts the security strategy from merely trying to prevent perimeter attacks to actively managing network security, acknowledging that perfect perimeter defense is unachievable. This mindset encourages continuous improvement of internal controls and rapid response strategies, ultimately strengthening the organization’s resilience against attacks.
The Pillars of Zero Trust_ Assuming Breach feat Chris Foulon & James Azar