It says most of the work is complete, but there may be some minor disruption to IT services today as systems are brought back online.
It has crippled Britain's health system - with stroke victims unable to undergo urgent surgery because their scans could not be accessed - and affected other businesses around the world.
The British government said 48 of 248 health service trusts - the bodies that run the hospitals - in England had been impacted by Friday's attack.
I am anxious about how the numbers will continue to grow when people go to work and turn on their machines on Monday morning.
The cyber attack which hit the NHS was a ransomware attack which encrypts files on a user's computer, blocking them from view and threatening to delete them unless a payment is made.
More than 200,000 victims in about 150 countries have been infected by the ransomware so far.
On Sunday night, Microsoft blamed the USA spy agency that had originally developed software that allowed the ransomware attack to infect computers.
"We're in the face of an escalating threat, the numbers are going up", he said, and added that the current attack was unprecedented.
Services in as many as 45 healthcare centers, including hospitals, came to a halt when the malicious malware hit computers from midday Friday. Microsoft released a patch over the weekend for the Eternal Blue vulnerability that defends against it even with older versions of Windows.
But speaking publicly for the first time since the cyberattack, Health Secretary Jeremy Hunt said that "according to the latest intelligence we have not seen a second wave of attacks".
The organisation told trusts: "Our Data Security Centre continues to work around the clock alongside the National Cyber Security Centre, to support NHS organisations that have reported any issues related to this cyber-attack".
The Daily Caller News Foundation talked to several tech experts about how to better protect people and institutions from cyber attacks and nefarious hackers.