be more vague or I won't even read it.
I assume you are at home now?
"a girl at work" - was she someone that was "supposed" to do this, as part of "her job" or was it just some girl wandering by installing stuff for fun... the firewall fairy perhaps?
do you know the name of the software that is installed?
do you know if it was authorized?
all in all - if they put it up, they don't want you on certain sites - they are trying to increase productivity - and if you get around it, they will likely see and you won't be enjoying your job so much.