My girlfriend [22/F] and I [24/M] have been together 6 months. There are now compromising pics / vids of her circulating in our social group.

We have been together for 6 months and everything has been going great. In all we're a great match for eachother and i'm really happy with our relationship but recently a close friend took me aside and told him that a number of videos and pics of her have been circulating around my social group, etc showing her naked, having sex with people, etc. I want to talk to her about this but I want to make sure I don't hurt her as it's entirely possible they were from before we were together. I'm also quite upset with my friends and acquaintances seeing these. How should I approach the topic with her?

tl;dr: Videos of my girlfriend naked / having sex with people have surfaced, I need to know how to talk to her sensitively about this.