The top three banks in the Netherlands have been targeted in multiple cyber attacks over the past week, blocking access to websites and internet banking services, they said on Monday.
The number one Dutch bank, ING, was hit by a so-called distributed denial of service (DDoS) attack on Sunday evening while the eurozone nation's third largest lender, ABN Amro, suffered three attacks over the weekend in a total of seven over the last week, Dutch media reported.
Rabobank, the country's number two lender, saw its internet banking services go down on Monday morning.
“We have been targeted by a DDoS attack since 9.10 am (0810 GMT) this morning (Monday) and our clients don't have access or very little access to online banking,” Rabobank spokeswoman Margo van Wijgerden said.
“We are working to resolve the problem as quickly as possible,” she told AFP.
ING, which has some eight million private clients, experienced an attack on Sunday evening, it said on its website.
“During the DDoS attack ING's internet site was blasted with data traffic causing our servers to overload and which put pressure on the availability of online banking,” ING said, adding services had been restored.
ABN Amro experienced a similar attack but also said services were restored.
It will “keep monitoring availability and is extra alert since the weekend's attacks,” it said in a statement.
The banks all stressed that clients' banking details were not compromised or leaked.
It is not the first time Dutch banks were targeted in a DDOS attack with central bank chief Klaas Knot telling a TV news programme Sunday there were “thousands of attacks a day” on his own institution.
“I think these (recent) attacks are serious, but our own website is being attacked thousands of times per day,” Knot told the Buitenhof talk show.
“That is the reality in 2018,” he said.