Yum! Brands, the owner of KFC, Pizza Hut and Taco Bell, has said less than 300 of its UK restaurants were closed following a ransomware attack earlier this week.
The company shut sites on Wednesday after certain IT systems were hit, but all locations have since reopened.
Yum! Brands said there was no evidence customer databases were stolen but data was taken from its network and an investigation is ongoing.
After detecting the incident, the company took certain systems offline and implemented enhanced monitoring technology.
It has also engaged the services of cybersecurity and forensics professionals, and notified Federal law enforcement.
"While this incident caused temporary disruption, the company is aware of no other restaurant disruptions and does not expect this event to have a material adverse impact on its business, operations or financial results," Yum! Brands said in a statement.
The company is based in Louisville, Kentucky and its subsidiaries franchise or operate a system of over 53,000 restaurants in 155 countries and territories. It also owns the Habit Burger Grill brand.