SOPHIE, a thriller by Bruce Allsman

Jason Macklin is a billionaire, a domotics pioneer and inventor of SOPHIE, Super Optimal Programmable Home Integration Environment, a state-of-the-art home automation system. Jason and his wife, Clarisse, live in their new home that is equipped with SOPHIE. When unusual things begin to happen, he investigates and discovers that a malicious hacker, Peter Newman, a former employee with an axe to grind, is gradually taking control of SOPHIE, in turn the home's hermetic environment thereby trapping him and his wife. Peter demands a huge ransom, an immediate payment by wire transfer, or he would use SOPHIE to kill them.