SEATTLE (AP) — Washington state is suing one of the world's largest independent tech support companies, saying it routinely scams customers into buying software and services they don't need.

Attorney General Bob Ferguson filed the lawsuit Wednesday against iYogi, which boasts of 3 million customers and which announced over the summer that it was opening its first U.S. technical support center in Lewiston, Maine.

During a news conference, Ferguson said iYogi employees often take remote control of the computers of people who seek help, make ominous warnings flash on the screen and then tell them they need to spend money to fix the virus.

Microsoft's chief legal officer, Brad Smith, joined the news conference and said iYogi is one of the companies that Microsoft receives the most complaints about.

An iYogi representative did not immediately return an email seeking comment.