TORONTO -- Class-action lawyers wasted little time Friday in jumping on word of a cyberattack on an Ontario casino in which sensitive information was stolen.

The lawyers announced plans for a proposed lawsuit that would seek $50 million in damages from Casino Rama north of Toronto, and began asking possible victims to sign on.

"The class action will be commenced on behalf of employees, customers and vendors of the Casino Rama Resort whose confidential information was compromised by the privacy breach," the lawyers said.

"The proposed representative plaintiffs in the lawsuit are customers who gave the resort their confidential information, including financial information."

The statement of claim would be filed in Superior Court on Monday given the Remembrance Day holiday on Friday, said lawyer Ted Charney, one of the lawyers involved.

On Thursday, Casino Rama Resort in Rama, Ont., warned its customers, vendors as well as current and former staff to keep an eye on their bank accounts, credit cards and other financial information. The casino said it had "recently" discovered becoming the victim of a cyberattack that resulted in the large-scale data theft.

Stolen data appeared to include internal financial and security-incident reports, emails, payroll data, client information, social insurance numbers, and dates of birth, according to the casino.

"The hacker claims that the employee information dates from 2004 to 2016, and that some of the other categories of information taken date back to 2007," the casino said in a statement on its website. "We can confirm that certain employee and customer information was stolen."

The statement also warned that the hacker could publish the stolen data.

"This is a massive privacy breach," Charney said in announcing the proposed lawsuit. "We still do not know the whole story but it looks like Casino Rama rolled the dice with employee, customer and vendor data rather than invest in state-of-the-art security measures."

No allegations have been tested in court and it was still much too early for any statement of defence.

"We continue to work with the proper authorities on the ongoing investigation and are limited in in how much detail we can provide," casino spokeswoman Jenna Hunter said in an email Friday. "We deeply regret the this situation and recognize the seriousness of the issue."

Any trial, should the action be certified, is likely years away.

The resort, which has 2,500 slot machines and more than 110 gaming tables and is operated by Penn National Gaming Inc., said the games themselves weren't hacked.

"Game performance and setup are independent of other Casino Rama Resort networks," it said.

Located on Rama First Nation, the casino opened 20 years ago and is Ontario's only First Nations commercial gaming house. It bills itself as the "premier entertainment destination" in the province and has featured big name live acts such as The Tragically Hip and Jerry Seinfeld, and shows such as "Dancing with the Stars."

The two law firms involved in the proposed action are Charney Lawyers and Sutts, Strosberg.