TORONTO — A Canadian-owned dating website for married people seeking affairs says it has suffered a cyber attack after hackers claimed to have stolen confidential customer information and threatened to publish it unless the company is shut down.Avid Life Media, which owns Toronto-based cheating site AshleyMadison.com, said Monday that it had taken steps to secure its sites.“We apologize for this unprovoked and criminal intrusion into our customers’ information,” the company said in a statement. “We have always had the confidentiality of our customers’ information foremost in our minds, and have had stringent security measures in place.”Adultery a booming business: AshleyMadison.com seeks London IPO as more women sign up to have affairsAshley Madison, dating website for married people, sues South Korea after being blockedAshley Madison, whose slogan is “Life is short. Have an affair,” claims it has more than 37 million anonymous members around the world.While its site appeared to be working normally Monday morning, an online security blog, KrebsOnSecurity.com, posted what appeared to be a screenshot of the site’s homepage on Sunday bearing a message from those allegedly behind the hack.“We are the Impact Team. We have taken over all systems in the entire office and production domains, all customer information databases, source code repositories, financial records, emails,” the message said, according to Krebs, before going on to demand that Ashley Madison, as well as another Avid Life Media site — EstablishedMen.com — be shut down.“Shutting down AM and EM will cost you, but non-compliance will cost you more,” the message said. “We will release all customer records, profiles with all customers’ secret sexual fantasies, nude pictures, and conversations and matching credit card transactions, real names and addresses, and employee documents and emails.”Whoever hacked the sites claimed they did so to expose alleged lies Ashley Madison told customers about a service that allows members to erase profile information for a $19 fee, Krebs reported. Avid Life Media said it had launched an investigation into the breach and employed a top IT security team to “take every possible step towards mitigating the attack.”“Our team has now successfully removed the all posts related to this incident as well as all personally identifiable information about our users published online,” the company said. “Our team of forensics experts and security professionals, in addition to law enforcement, are continuing to investigate this incident.”Avid Life Media also owns a website called Cougarlife.com.The company said all its sites had been secured, with all unauthorized access points closed. It added that it had “stringent security measures in place,” but noted that the current online environment was one where no company’s online assets were safe from cyber vandalism.The Ashley Madison breach comes about two months after dating site AdultFriendFinder.com suffered a cyber attack.