What is the most common kind of zero day malware?

Zero day malware is a type of malware that is not yet known to the anti-virus software application.  https://sakeradvantage.com/?p=869 The most typical type of no day malware is a trojan horse. A trojan horse is a type of malware that disguises itself as a safe program in order to get access to a system. https://9tolife.co.uk/?p=669