Hackers may have just cost the Ashley Madison affair site $200 million

A blackmail cyber attack has hit affair site Ashley Madison, mere months after the company announced plans to launch a $200 million Initial public offering (IPO) later this year.

The attack was spotted by independent security journalist Brian Krebs on Sunday.

It saw hackers, operating under the name "Impact Team" use an unspecified method to breach Avid Life Media (ALM) - a Toronto-based company that owns Ashley Madison and a number of other "hookup sites," such as Cougar Life and Established Men.

Following the breach Impact team leaked a small percentage of the site's 37 million users account data online. This included the users real names and addresses.

The leaked data also included maps of ALM internal company servers, employee network account information, company bank account data and salary information.

Bloomberg reported Ashley Madison planned to make an initial public offering in London in April, where it hopes to raise as much as $200 million. The IPO was planned to occur at an unspecified point later this year. However, the devastating data breach leaves this in doubt.

It is likely to heavily shake customer confidence (and hence the company's finance performance), as well as investors' perception of the company - two important factors in any IPO. ALM declined Business Insider's request for comment on how the attack will affect its plans.

ALM has since issued a statement listing the attack is a simple act of "cyber vandalism" and has brought in specialists from security firm Cycura to plug the undisclosed security holes.

Krebs said the weekend attack was designed to protest-slash-punish the site for selling an allegedly bogus full delete service, previously reported on by Ars Technica.

The feature promises to completely purge customers' information from ALM's database for a $19 fee. However, according to Krebs, Impact Team believes the service is "a complete lie," and doesn't actually delete the paying customer's information.

The hackers have since pledged to continue publishing stolen ALM data online until the firm shuts down Ashley Madison and Established Men.

"Avid Life Media has been instructed to take Ashley Madison and Established Men offline permanently in all forms, or we will release all customer records, including profiles with all the customers' secret sexual fantasies and matching credit card transactions, real names and addresses, and employee documents and emails. The other websites may stay online," read the hacker's manifesto, published on Krebs Security.