Here is what you need to do if you are worried about SoakSoak WordPress Malware Virus Hack.
SoakSoak appeared in mid December 2014. At the time of writing (17 December) it has already infected over 100,000 WordPress sites. It appears to be exploiting a vulnerability in RevSlider, and can infect not only the site where it gains entry, but also other sites on the same server.
To prevent getting this, it is ALWAYS a good idea to not only make sure all your plugins are up to date, but also to remove any inactive plugins. Also, install a good anti-hacking plugin like iThemes Security or the Sucuri plugin, configure it and check it frequently.
Here are some other posts I have done about WordPress Security.
To detect whether your site has Malware, go to the Sucuri Site Check page.
If your site has been affected, you should talk with your web site builder about getting it fixed. Or, if you don’t have someone like that, Sucuri offers such a service.
If you prefer to try to fix it yourself, this page on the Sucuri blog has the instructions.