The targeted organizations are the Bank of Montreal (BMO) and Simplii Financial, the direct banking brand of the Canadian Imperial Bank of Commerce (CIBC). Both BMO and CIBC are among Canada’s five largest banks.

BMO believes the incident impacts less than 50,000 of its 8 million customers, and Simplii Financial says hackers may have obtained information on roughly 40,000 clients.

Both banks were contacted by hackers on Sunday. Individuals claiming to be behind the attacks told Canadian media outlets they had demanded a $1 million ransom from each bank. If the organizations refuse to pay, the information, which allegedly includes social insurance numbers, dates of birth, and financial information, would be sold to fraudsters.

BMO, which believes the attack originated from outside the country, says it has contacted authorities and potentially impacted customers.

While neither of the banks has confirmed suffering a data breach, BMO says it’s “confident that exposures identified related to customer data have been closed off.” Simplii says it’s taking the claim seriously and it has quickly implemented “enhanced online fraud monitoring and online banking security measures.”

Simplii has found no evidence that customers who bank through CIBC directly are impacted. “If a client is a victim of fraud because of this issue, we will return 100% of the money lost from the affected bank account,” the company stated.

While hackers may have gained access to the systems of Simplii and BMO, overblown claims are not uncommon in extortion schemes. There is also the possibility that the data is legitimate but was obtained by cybercriminals through other means, such as phishing, rather than by directly breaching the banks.

On the other hand, hackers breaching the systems of banks is not unheard of. Financial organizations in the United States, Mexico, India, Russia, and Taiwan were targeted recently in sophisticated cyber attacks and had either millions of dollars or sensitive customer information stolen.

National Security Minister Stuart Young, who was called out of the Cabinet meeting on Thursday and informed of the hack, said both websites have since been shut down.

“There are currently investigations as to where this hacking could have taken place from and we have shut down the websites…until we’re able to secure them and understand, what, if anything, has happened.”

Young assured that there was no real damage done by the hack.

“These websites don’t get into our operating systems; these websites are not going to affect the records at National Security, certainly not the records at Immigration either.”

The Minister said there was no reason to be overly concerned about an “intentional attack” on data from either entity.