integral87 answered your question: omg fusco baby plz be safe ;_;

It says “security breached”, does it mean that someone broke into the Machine and now targeting people who somehow involved with it?

It’s not just security breached, it’s “system administrator security breached.”  I think The Machine is freaking out because they’ve both gained valuable information on Finch’s past.  Apparently a threat to Finch is a threat to the system.  But the real question is, did Finch program The Machine to watch his back, or is it acting on its own?