While (most) Australians were sleeping, Ubisoft's UPlay service was discovered to be compromised. Thankfully, before (most) Australians woke up, Ubisoft had already addressed the issue.
Exploiting a problem with its UPlay browser plug-in, part of Ubisoft's DRM portfolio arbitrary code could be run on a user's system, instead of just the UPlay application.
UPlay itself should auto-update to version 2.0.4 when next opened, fixing the issue, but if you want to make sure, you can re-download it from Ubisoft's website and update it with all browser windows closed.
Alternately, you can disable the browser plug-ins by using the methods here.