A zero day cyber attack sounds ominous, but it simply means that the attack was discovered on the current day. The manufacturer of the software being attacked (in this case Microsoft’s Internet Explorer) hasn’t yet had time to deal with the software weakness that’s being exploited in the attack.
As I have mentioned before on this blog, most cyber attacks take advantage of bugs or weaknesses in software. Since software developers are human, it’s pretty easy to prove that every piece of software has bugs. The question is just how hard they are to find.
In the case discussed in this article from CRN, Microsoft has discovered a weakness that affects every supported version of Internet Explorer.
This also illustrates the importance of avoiding links in emails that you don’t trust. Simply visiting an infected site can infect your computer. Take a look at the article for more information about specifically what is being done by this cyber attack.