By now you would have heard about the Heartbleed software bug that has affected approximately two thirds of internet based services.
Many service providers (banks, shopping, social networks, etc.) have issued statements recommending that you change your password because they cannot guarantee it is still secure. If you use the same password to connect to these services, you should consider changing it as a precaution and to be on the safe side.
You should also check with those providers that they have taken precautions and fixed the problem to their websites.
For more information please follow the link below.
Source: Panda Security