In a statement published on its website on Monday, the Cactus management added that its Bonnevoie and Merl stores would reopen from Tuesday.

“We confirm that we were victim of a hacking attack,” it wrote. The supermarket chain says it has filed a complaint with the judicial police and has "informed the competent authorities," about the attack.

The three shops were forced to close on Wednesday. At the time, the chain cited technical problems. On Thursday, it announced its system had been hacked. But Cactus insisted that its card payments system had not been compromised.

A March report from Europe’s police network, Europol, found an explosion in cybercrime as criminals exploit the covid-19 crisis. And it is not only businesses that are the target.

In March, health minister Paulette Lenert (LSAP) said in a press conference in March that local hospitals were subject to attempted cyberattacks on a daily basis but cyber security measures had been effective in blocking them.