Following a cyberattack on a number of companies in Sweden, the severely affected supermarket chain Coop has reopened hundreds of its stores again.
According to a list published by the company, about 550 of the roughly 800 Swedish Coop branches were up and running on Tuesday, with some 250 still closed.
In many of the reopened shops, payment was only possible via an app, however, as technicians were working on getting the checkout systems to operate again.
Coop is one of the leading supermarket chains in Sweden.
Starting on Friday evening, there had been an attack on a service provider for Coop, which affected both the normal checkout systems and self-service checkouts of the supermarkets. Hundreds of other companies were also targeted by the cyberattack.
The company was forced to close almost all of its stores over the weekend due to the attack.
On Sunday, it managed to switch to payment via its in-house "Scan & Pay" app in at least some of its branches. Coop has since filed a complaint.
The ransomware attack wasn't directed at the supermarket chain itself but at US IT service provider Kaseya, with hackers exploiting a security gap at the company.
Ransomware attacks encrypt data on computers. The attackers usually demand a ransom for the release of the data.
A hacker group is now demanding 70 million dollars in the digital currency Bitcoin for a master key to all affected computers.