Cybersecurity Controls for Enhanced Network Protection

In a recent assessment project on a network, alarming symptoms indicative of a cyberattack were identified. These included unusual antivirus scanning logs and the unauthorized creation of user accounts on the Windows Active Directory. A detailed investigation revealed a PowerShell-based attack, and two critical Windows servers were found to be significantly under-patched: one Active Directory controller lagging by three updates, and a SQL server lagging by seven updates. Notably, the patch update for the SQL server had been deliberately delayed maintaining backward compatibility for a frontend application.

Furthermore, one Windows client machine exhibited signs of being a potential Indicator of Compromise (IoC). From this compromised client, elevated privileges were executed, and PowerShell logins were made to both the SQL server and the Active Directory controller.

To fortify the network against such vulnerabilities and ensure robust cybersecurity, the following controls should be implemented:

1. Regular Patch Management

Ensuring all systems are regularly updated is paramount. This includes:

• Automated Patch Deployment: Use automated tools to deploy patches across all systems as soon as they are released.
• Patch Testing Environment: Maintain a dedicated environment for testing patches before deployment to avoid compatibility issues.

2. Enhanced Antivirus and Anti-Malware Solutions

Deploy advanced antivirus and anti-malware tools that offer real-time protection and behavioral analysis to detect and mitigate threats effectively.

3. PowerShell Security Measures

Given the identified PowerShell attack, the following controls are crucial:

• Constrained Language Mode: Enforce Constrained Language Mode in PowerShell to limit the capabilities available to scripts.
• Script Block Logging: Enable PowerShell script block logging to monitor and log all executed scripts for forensic analysis.
• Execution Policy Restrictions: Set restrictive execution policies to prevent unauthorized scripts from running.

4. Active Directory Hardening

Secure Active Directory by implementing:

• Least Privilege Principle: Limit administrative privileges and ensure users have the minimum access necessary for their roles.
• Regular Audits: Conduct regular audits of Active Directory to identify and remove unauthorized accounts.
• Multi-Factor Authentication (MFA): Implement MFA for all administrative accounts to add an additional layer of security.

5. SQL Server Security

To safeguard the SQL server:

• Apply Updates Promptly: Ensure SQL servers are updated promptly to mitigate known vulnerabilities.
• Database Access Controls: Implement strict access controls and regular review of permissions.
• Network Segmentation: Segment SQL servers from the rest of the network to minimize the attack surface.

6. Network Monitoring and Incident Response

Establish comprehensive network monitoring and incident response protocols:

• Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS): Deploy IDS and IPS to detect and prevent suspicious activities.
• Security Information and Event Management (SIEM): Utilize SIEM solutions to aggregate and analyze logs from various sources for real-time threat detection.
• Incident Response Plan: Develop and regularly update an incident response plan to quickly address and mitigate security breaches.

7. User Awareness and Training

Educate users on cybersecurity best practices through regular training programs to ensure they are aware of potential threats and how to respond appropriately.

8. Regular Security Assessments and Penetration Testing

Conduct regular security assessments and penetration testing to identify and address vulnerabilities before they can be exploited by attackers.

9. Data Backup and Recovery Plans

Maintain robust data backup and recovery plans to ensure data integrity and availability in the event of a cyberattack.