Zero-day exploits are security loopholes in software that allow hackers to exploit systems for malicious purposes. A hacker can use a zero-day exploit to launch attacks, such as ransomware or data theft. To protect against this type of exploit, organizations should:

1. Keep Systems Up to Date: Install security patches when they become available, enabling systems to have the latest bug fixes and security features.
2. Perform Regular Vulnerability Scans: Regularly scan systems and networks for security holes and other issues that could allow zero-day exploits to occur.
3. Use Antivirus Software with Scanning Capabilities: Utilize antivirus software with scanning capabilities to detect and remove malicious code from networks and connected systems.
4. Implement a Firewall: Enable a firewall to help block malicious code and traffic reaching and attacking your network.
5. Enable Logging and Monitoring: Enable logging to review system activity and monitor for suspicious behavior.