According to a report by WatchGuard 2016, 30% of malware attacks are zero-day exploits that cannot be detected by antivirus systems because they never before seen attack. Zero-day exploits are unknown exploits in the wild that expose vulnerability and can lead complicated problem before anyone realizes the problem. For this reason, zero day exploits are hard to detect at first. Zero-day exploits has a singular purpose to deliver malware to unsuspecting victims, but come in several shapes. The most dangerous zero-day exploits facilitate drive-by-downloads by clicking malicious links or browsing to an exploited website. Such attacks can result in a full-fledged malware attack on your software/hardware. Zero-day attack also can exploit vulnerabilities within Microsoft Word, PowerPoint, Excel, and Adobe products. Flaws in such software can be used to target enterprise and government agencies. Zero-day attack happens once vulnerability is exploited. Attackers find vulnerability and release malware before developers have chance to fix it. When developers create software they do not realize that it contains vulnerability. Attackers find vulnerability before developers realize it or have opportunity to fix it. Attackers write and implement exploit code while the vulnerability is still available. After releasing exploit, it could be recognized it in the form of identity or sensitive information theft. Developers create a patch to fix the problem. Once a patch is applied, the exploit is no longer called a zero-day exploit. Normally, these attacks are not discovered right away. It often takes several months or years before developers catch the vulnerability to fix it. No network guarantees 100 percent safe from Zero-day exploits. To protect against zero-day attacks, simply individuals never click on suspicious link and download files or unknown source. Business enterprises and organization can also use certain security device or procedures to ensure the safety your system against zero-day attacks.