Friday, July 2: First payment problems
The first problems arose on Friday evening at 7 pm and included both self-payment cash registers and staffed cash registers.
Several of the country's 800 Coop stores were forced to close when they could not charge their customers.
Saturday, July 3: Confirmed IT attack
It is confirmed that it is an IT attack against a supplier to Coop, which caused the cash register crash on Friday.
The attack was not aimed at Coop but the American company Kaseya, whose software is in turn used by Coop's supplier Visma Esscom.
When SVT Nyheter spoke to Coop on Saturday morning, they had made the decision to keep most of the stores closed.
Therese Knapp, spokesperson for Coop, said on Saturday that the accident is nationwide.
Apotek Hjärtat, the petrol chain St1 and the train company SJ have also been affected by disruptions in their systems.
Sunday, July 4: Joe Biden demands investigation
The majority of Coop's stores are forced to remain closed.
Fabian Mogren, CEO of Visma Esscom, says that they must restore the computers locally in the stores.
- We have a couple of hundred men on this who work around the clock, computer for computer, store for store, says Fabian Mogren to TT.
Joe Biden is ordering US intelligence to conduct a full-scale investigation into speculation that the Russian Kremlin may be involved in the attack.
One of the priority goals of the investigation is to find out who is behind the attack.
Monday 5 July: The hackers demand SEK 600 million
The hackers who are believed to be behind the massive cyber attack that has affected hundreds of companies globally are demanding 70 million dollars, equivalent to almost 600 million kronor, to reopen the systems.
The extortion claim has been published on the hacker group Revil's blog.
- I'm not a bit surprised, says Minister of Defense Peter Hultqvist in SVT's Morgonstudion.