Firstly, I can't be sure it is this plugin with the fault, however the issue only occured after installing the plugin yesterday. Also, I have disabled this plugin only (leaving others enabled) and the issue has gone away... for now...
While I am monitoring I just wanted to put this out there to see if anyone else is experiencing the issue?
URL friv.webeden.co.uk has been injected top left hand side of each page.
Looking at a google search its happening to a lot of sites
Again I'm not blaming this plugin as I have no proof its what caused it.