Well one of the biggest computer sellers known as "Lenovo" has recently been selling PCs with malware called "Superfish", The superfish malware analyzes users Internet Habits and injects third-party advertisement into websites on browsers such as Google Chrome & Internet Explorer without the users permission.
Here is guide on how to remove this - https://www.eff.org/deeplinks/2015/02/how-remove-superfish-adware-your-lenovo-computer
Source: http://thehackernews.com/2015/02/lenovo-superfish-malware.html
Here is guide on how to remove this - https://www.eff.org/deeplinks/2015/02/how-remove-superfish-adware-your-lenovo-computer
Source: http://thehackernews.com/2015/02/lenovo-superfish-malware.html