Company's Sandouville plant in northwestern France was one of the factories that stopped production.
Renault expects to be able to resume normal production on Monday in the factories that were hit by a global cyberattack.
Auto production was halted in Slovenia after computers at the headquarters of Renault's subsidiary Revoz in Novo Mesto were affected, a spokeswoman told AFP.
"Production was affected overnight but luckily there was no full production scheduled for this weekend, only some "stamping" operations", he said.
Earlier Saturday, the spokeswoman had said the problems were mainly related to France, and had also affected the company's IT systems.
"Efforts to localise the infected server are underway to prevent (the ransomware) from spreading", he said, adding that his ministry was working with other authorities, including the Health Ministry, to solve the problem.More news: Global 'WannaCry' ransomware cyberattack seeks cash for data
An English plant of Renault's alliance partner Nissan was also hit by the attack.
A spokesman for Renault said that proactive measures have now been put in place, so here's hoping that included a basic Windows update that IT should've been on two months ago.
The company's management confirmed the cyber attack said on Saturday. The probe covers "Renault and other possible victims", the source said.
Renault is the first French company to confirm it has been affected by Friday's wave of cyberattacks, which apparently exploited a flaw exposed in documents leaked from the US National Security Agency. "Like many organizations, our United Kingdom plant was subject to a ransomware attack affecting some of our systems on Friday evening".
The Newcastle Evening Chronicle reported, that production was briefly halted Friday evening.