Warning: answer is basically spoilers
She didn't do it to avoid being a victim of identity theft, she knew that as her identity and bank accounts were compromised, there was always going to be the blackmail risk or risk of betrayal from the thief. She did it as a way of ruining her boyfriend's life.
Her boyfriend was the one who's actions lead to her identity being stolen, and the images of her being taken, by putting a CD of unknown origin in his laptop. Anyone who is remotely involved in IT security should know not to do that. Even a sales person. On top of that her boyfriend was also cheating on her and exchanging messages which made her feel humiliated.
When she infected the Allsafe network, she did it from her boyfriend's machine, knowing it would likely be traced back to him and be seen as a direct attack from the inside.
Having been distanced by Elliot because of his actions and what he's going through, and humiliated by the Evil Corp exec and her boyfriend, she doesn't want to be at Allsafe. She feels she's lost everything anyway, and by doing this the company will be destroyed, they will all lose their jobs, and she gets to start a fresh whilst getting revenge.