Wandering Eye (2011) on Netflix

Plot summary

Maren Abbott is a young wife whose husband, Dr. Connor Abbott, is a workaholic surgeon, and their marriage leaves her neglected. She signs up for Wandering Eye, a networking website built for extramarital liaisons, and meets a charming man through it. She agrees to meet him in a hotel room, but once she is there Maren decides she cannot go through with the affair. The man is then found brutally murdered in that same hotel room. The same website is how a serial killer chooses his victims, and Maren, who signed up for the site herself, becomes one of his targets.