What is it?
The Heartbleed bug is a flaw in software used to secure many popular web sites including Google, Facebook, Dropbox and Minecraft. It is not isolated to a companies or websites but affects many of the most popular sites. In terms of impact to security on the internet on a scale of 1 – 10 this is an 11. What the Heartbleed bug is not is a virus. Antivirus software will not help you with Heartbleed.
The bug allows hackers to gain access to your private information you have on these systems. The link below shows how a hacker could get your information.
What to do about it?
So now that you know what the Heartbleed flaw is, what can you do about it. The best way to prevent your personal information from being accessed is to change passwords on sites that have had the bug. You will need to wait until the software on each website if fixed before you go ahead and change your password. In order to know what websites are affected, and when they have been fixed reference the link below.
http://mashable.com/2014/04/09/heartbleed-bug-websites-affected/
For even more information on the Heartbleed check out the Wikipedia page
http://en.wikipedia.org/wiki/Heartbleed