The Art of Cyber Defense: Insights from a Pen Tester

The Importance of Network Segmentation

One of the top tips for securing organizational data and protecting against potential cyber attacks is implementing network segmentation. Network segmentation refers to the practice of logically separating different parts of a network to create barriers and restrict access between them. Despite cybersecurity experts preaching its benefits, only 25% of organizations actually implement network segmentation, according to data cited by CIO.

Without network segmentation, organizations face significant challenges in securing their networks. Every employee and device will have access to the same network, making it difficult to protect critical information and prevent unauthorized access. This lack of segmentation becomes particularly problematic when seemingly harmless devices, such as printers, can pose a threat to the network.

For instance, during a physical penetration test conducted for a large airline, consultants were able to gain access to the airline’s internal network through a printer at the gate, without encountering any employee intervention. This example highlights the need to implement access controls, such as passwords or user authentication, and to keep firmware up to date to address any known vulnerabilities.

In addition, organizations should ensure that their corporate backup solutions are not easily accessible to everyone, as threat actors could potentially delete backups and unleash ransomware. Network segmentation would isolate printers and other devices from the rest of the network, limiting the potential impact of a security breach.

Firewall access controls should also be established between internal network segments to restrict access to network resources in the event of an attack. Furthermore, physical or logical access control measures should be implemented to prevent unauthorized physical access to devices.

Modernizing Your Network

Upgrading and modernizing your network plays a crucial role in enhancing network security. Microsoft has made significant progress in improving the security of Windows and Windows networking over the past 30 years. However, many organizations still rely on legacy solutions that date back to operating systems like Windows 95 or even Windows for Workgroups.

Investing in modern operating systems, such as Windows 10 or 11, and Windows Server 2016 or newer, allows organizations to disable backward compatibility and eliminate potential vulnerabilities tied to outdated systems. Enabling “native mode domain” helps strengthen network security and reduce security risks associated with unsupported or end-of-life solutions.

It is crucial for organizations to upgrade their legacy systems and ensure that all software is regularly patched through a vulnerability management and remediation program. By doing so, organizations can minimize the exposure to known vulnerabilities and strengthen their overall cybersecurity posture.

Improved Visibility with Content Filtering

To enhance a firewall’s visibility into outgoing traffic and protect against potential threats, implementing content filtering is essential. Content filtering allows organizations to control the type of sites that can be accessed, limiting the avenues through which attackers can exploit vulnerabilities.

Organizations should consider whether their employees are on the corporate network or working remotely. While a work-from-home culture may not scale well in terms of network security, it is crucial to ensure that server systems do not have unrestricted access to the Internet. Leveraging solutions such as content filtering can help control the websites that can be accessed, making it harder for attackers to exploit an organization.

For example, blocking access to common file-sharing sites like Mega.io, frequently used by ransomware threat actors to exfiltrate data, can be an effective measure in stopping data breaches. Content-filtering options such as Zscaler or DNS monitoring solutions like Cisco Umbrella are useful for controlling the type of websites that corporate devices can access in non-traditional office environments. These solutions also provide monitoring capabilities to detect and respond to potential phishing attacks.

It is important to remember that even in remote work scenarios, corporate assets should remain under the control of the organization. Basic protections like firewalls, while still necessary, are minimally effective against the ever-evolving threat landscape. Implementing network segmentation, modernizing your network infrastructure, and leveraging content filtering solutions are vital steps to staying ahead of attackers and maintaining visibility into your entire environment.

Conclusion

In a world where cyber threats continue to grow in complexity and magnitude, organizations must prioritize their cybersecurity measures. Implementing network segmentation, modernizing network infrastructure, and utilizing content filtering solutions are crucial steps for all organizations.

Network segmentation provides a logical separation between critical information and everyday employees, creating barriers and restricting access. Modernizing network infrastructure by eliminating legacy solutions and ensuring regular software updates enhances overall security. Content filtering improves visibility into outgoing traffic and allows organizations to control access to potentially harmful websites.

Organizations cannot afford to lag behind when it comes to cybersecurity. By implementing these three essential measures, organizations can proactively protect their data, prevent potential cyber attacks, and maintain a robust cybersecurity posture in today’s evolving threat landscape.