Computer Security Day on November 30 is a special date established to remind us how important it is to keep our computers safe. It was created to raise awareness of cyber security issues after the devastating effects of the Jerusalem virus. New malware is more subtle, silent and unobtrusive, but extremely effective. Protecting against these silent threats is the new challenge. Only 0.33% of the threats we detect try to infect or delete operating system files. The Jerusalem virus caused a worldwide epidemic for the first time in 1988.”]