From the last few days every one is talking about this topic, First of all I would like to inform you Heartbleed not a virus its a BUG.
Heartbleed has already been exploited by hackers in China,accordingly News and some of blogs Mashable published a report that shows the passwords on websites that one needs to change right away.
Some of experts views:
The Heartbleed Bug is a vulnerability in the OpenSSL cryptographic library that allows attackers to invisibly read sensitive data from a web server. This potentially includes cryptographic keys, usernames, and passwords.