San Mateo, California-based PerimeterX, a provider of behavior-based threat protection technology, has raised $23 million in a Series B round of funding led by Canaan Partners. Existing investors Vertex Ventures and Data Collective also participated in the round. As part of the funding, Joydeep Bhattacharrya, a partner at Canaan, has also joined the board. The company previously raised $11.5 million from investors.