Minnesota's attorney general is partnering with federal authorities and officials in more than a dozen states to go after "tech support" scammers who persuade customers to buy unneeded, and often fake, antivirus protection.

Keith Ellison said Thursday that his office would be pursuing a default judgment in a lawsuit filed against a Bloomington company accused of tricking customers into believing that their computers would be disabled if they didn't pay for its services. He said the office fielded more than 300 similar complaints last year.

"You can be sure that those 300 tech support complaints are just scratching the surface," Ellison said. "Illegitimate tech support scams … rob our whole economy of something it depends upon to operate, which is trust and honesty."

Ellison said he has since joined 16 other state attorneys general and the District of Columbia in a yearlong "Tech Support Sweep" partnership with Justice Department and Federal Trade Commission investigators.

On Thursday, the attorney general released details of an undercover investigation into Bloomington-based Teknicians Inc., including playing a recording of a phone call with a representative who tried to sell the investigator support services to patch up viruses that did not exist on her computer. The representative also allegedly maintained remote access of her computer and activated her computer's video camera after the phone call ended.

Officials from Teknicians could not be reached for comment. The company has not responded to the lawsuit in any court filings.

Valerie Johnson of Hoffman, Minn., described receiving a sudden alert one day on her computer telling her that her virus protection expired. After buying virus protection for $199, she was later notified that her computer was infected with pornography, and the scammer withdrew funds from her bank account despite claiming it could fix the problem for free. All told, she lost $1,100 before calling the Attorney General's Office.

"It affects people no matter who you are, and it makes you feel so darn foolish," Johnson said, tearing up. "I don't want anybody else to have to go through this and have to explain to your family what you did."

Nathan Austin, vice president of business development at MyTech Partners in Minneapolis, said even his company was subjected to a scam when a Florida business began scamming "hundreds of thousands" of customers by using MyTech's name to give the impression that it was a legit company. Austin said his company learned of the fraud when it began receiving complaints from people demanding that charges be removed from their credit cards.

Austin recommended doing business with local technicians whom customers can meet in person and assess their legitimacy, and to be suspicious of those who contact customers who haven't asked for help in the first place.

"One of the things that I love about this state is we as Minnesotans are generally very trusting people, and it's unfortunate that these individuals, these bad actors, prey on that trust which is really part of the fabric of our society and our community."