A great deal of modern malware makes use of what is called polymorphic techniques. A number of vendors are using these techniques to keep malware from infecting endpoints. The techniques originally were called a moving target defense by several academics who held a conference last November in Arizona. But now the good guys are turning the tables and employing some of the same kinds of evasive techniques as protective measures. It is still too early to determine if these defensive products can stay ahead of the bad guys.”]
Source: https://securityintelligence.com/what-is-polymorphic-malware-and-why-should-i-care/