What is zero-day malware?
Zero-day malware is a special type of malware or malicious software that was recently discovered. In general, a zero-day phenomenon is one that was previously unknown or not predicted. Security teams respond to zero-day malware and other zero-day events and track their ability to fix them in real time.
Zero-day malware can affect specific operating systems in certain ways. Some types of malware infiltrate a system that is attached to email or otherwise disguised as harmless files. Others manipulate wireless or IP network security protocols. For example, many instances of zero-day malware that affect the Microsoft Internet Explorer browser have been addressed by Microsoft in the past. Many instances of zero-day malware are fixed with security upgrades or software patches.
In general, IT pros will use the term zero-day malware to indicate that malware is brand new and therefore teams may not have many resources to combat it with. Over time, the developer and security communities build these resources.
The term zero-day malware is a useful marker to show that there is a new threat and that it needs to be documented and resolved as soon as possible.