Security leaders face a big challenge: securing an environment where failure is not an option. Reliance on traditional security postures like Endpoint Detection and Response (EDR) to pursue threats that have already entered the network is fundamentally risky and contributes significantly to the half-trillion-dollar annual cost of cybercrime.
Zero Trust fundamentally changes this approach, transitioning from reacting to symptoms to proactively solving the underlying problem. Application control, the ability to strictly define what software is allowed to execute, is the foundation of this strategy. However, even once an application is trusted it can still be misused. This is where ThreatLocker RingFencing™, or granular application prevention, becomes indispensable, enforcing the ultimate standard of least privilege on all authorized applications.
Defining ringfencing: security beyond the allow list
Ringfencing is an advanced prevention strategy that applies to applications that have already been approved to run. While allow lists ensure a fundamental deny-by-default status for all unknown software, ringfencing restricts this further. capabilities of permitted software. It operates by dictating exactly what an application can access, including files, registry keys, network resources, and other applications or processes.
This detailed control is important because threat actors often circumvent security controls by abusing legitimate, approved software, a technique commonly referred to as “staycations.” Undocumented applications such as productivity suites or scripting tools can be weaponized to spawn risky child processes (such as PowerShell or Command Prompt) or communicate with unauthorized external servers.
Security Essentials: Preventing Redundancy
Without effective prevention, security teams are left with wide-open attack vectors that directly lead to high-impact incidents.
- Reducing Lateral Movement: Ringfencing isolates application behavior, hindering the ability of compromised processes to move across the network. Policies can be set to restrict outbound network traffic, a measure that would thwart larger attacks that relied on servers reaching out to malicious endpoints for instructions.
- High-risk applications containing: An important use case is reducing the risk associated with legacy files or scripts, such as Office macros. By implementing prevention, applications such as Word or Excel, even if required by departments such as finance banned from launching Access to high-risk script engines or high-risk directories, such as Powershell.
- Preventing data exfiltration and encryption: Prevention policies can limit an application’s ability to read or write to sensitive monitored paths (such as Documents folders or backup directories), effectively preventing large-scale data exfiltration attempts and preventing ransomware from encrypting files outside its specified scope.
Ringfencing naturally supports compliance goals by ensuring that all applications operate strictly with the permissions they actually need, aligning security efforts with best practice standards such as CIS controls.
Mechanics: How Granular Prevention Works
Ringfencing policies provide comprehensive control over multiple vectors of application behavior, acting as a second layer of defense after execution is permitted.
A policy dictates whether an application can access certain files and folders or make changes to the system registry. Most importantly, it controls inter-process communication (IPC), ensuring that an approved application cannot interact with or spawn unauthorized child processes. For example, Ringfencing prevents Word from launching PowerShell or other unauthorized child processes.
Implementing Application Containment
Adoption of ringfencing requires a disciplined, phased implementation focused on avoiding operational disruption and political fallout.
establishing a baseline
Implementation begins by deploying a monitoring agent to establish visibility. The agent must first be deployed in a small test group or isolated test organization – often affectionately called a guinea pig – to monitor activity. In this initial learning mode, the system logs all executions, upgrades, and network activity without blocking anything.
Emulation and enforcement
Before securing any policies, the team should use integrated audits to run a simulation (simulated denial). This preemptive auditing shows exactly which actions will be blocked when the new policy is implemented, allowing security professionals to create the necessary exceptions in advance and prevent the IT department from lowering its approval rating.
Ringfencing policies are typically created and implemented first on applications identified as high risk, such as PowerShell, Command Prompt, Registry Editor, and 7-Zip, because they have a higher potential for weaponization. Teams should ensure they have been properly tested before moving into a safe, enforced situation.
scaling and refinement
Once policies are validated in a test environment, deployment is gradually expanded throughout the organization, typically starting with the easy wins and gradually moving toward the hardest-hit groups. Policies should be constantly reviewed and improved, including regular deletion of unused policies, to reduce administrative clutter.
Strategic deployment and best practices
To maximize the benefits of application control while minimizing user friction, leaders should follow proven strategies:
- Start small and step by step: Always apply new ringfencing policies to the non-critical test group first. Avoid solving all business problems at once; Deal with highly dangerous software (such as Russian remote access tools) first, and delay political decisions (such as blocking games) until later stages.
- Continuous monitoring: To ensure legitimate operations are not disrupted, regularly review integrated audits and check for spurious denials before securing any policies.
- Combination Control: Ringfencing is most effective when combined with application permission lists (right-by-default). It should also be combined with storage controls to protect critical data to prevent large-scale data loss or intrusion.
- Prioritize configuration checking: Use automated tools such as Defense Against Configuration (DAC) to verify that ringfencing and other security measures are properly configured on all endpoints, highlighting where settings are missed in monitor-only mode.
Results and organizational benefits
By implementing ringfencing, organizations transition from a reactive model – where highly paid cybersecurity professionals spend time chasing alerts – to a proactive, hardened architecture.
This approach provides significant value beyond just security:
- operating efficiency: Application control is significantly reduced Security Operations Center (SOC) Alerts-Up to 90% in some cases -Resulting in less alert fatigue and substantial savings in time and resources.
- Enhancing Security: It prevents misuse of trusted programs, contains threats, and makes a cybercriminal’s life as difficult as possible.
- Business Value: This reduces application overreach without breaking business-critical workflows, such as workflows required by finance departments for legacy macros.
Ultimately, ringfencing reinforces the zero trust mindset, ensuring that every application, user, and device operates strictly within the boundaries of its essential function, making detection and response really a backup plan rather than a primary defense.
