By now you must have heard about the vulnerability that has existed for quite some time in supposedly secure websites that use Open SSL security. Many programs you use have been affected, and you should definitely change your passwords for Yahoo!, Google, Dropbox, USAA, Netflix, Pinterest, and OkCupid, for a start. You can find a list of other programs on this post from Mashable.
If you have an e-commerce ( https://) site you should check it for vulnerability to make sure it is safe.
If your WordPress site is using JetPack plugins, you must update the plugin to the latest version to address a vulnerability that was found in that popular set of plugins. This was so important that some web hosts like Bluehost have been updating JetPack on their customers’ sites. New Tricks has updated it for our Maintenance clients. But if you don’t fall into either of these categories and you are using JetPack, you should check that your site is running the latest version.