Where the attack hit hardest

EUROPEAN UNION: Europol’s European Cybercrime Centre, known as EC3, said the attack “is at an unprecedented level and will require a complex international investigation to identify the culprits.” BRITAIN: Britain’s home secretary said the “ransomware” attack hit 1 in 5 of 248 National Health Service groups, forcing hospitals to cancel or delay treatments for thousands of patients. GERMANY: The national railway said Saturday that departure and arrival display screens at its train stations were affected, but there was no impact on actual train services.

RUSSIA: Two security firms — Kaspersky Lab and Avast — said Russia was hit hardest by the attack. The Russian Interior Ministry, which runs the country’s police, confirmed it was among those that fell victim to the “ransomware.”

UNITED STATES: FedEx Corp. reported that its Windows computers were “experiencing interference” from malware but wouldn’t say if it had been hit by ransomware. Other impacts in the U.S. were not readily apparent.

TURKEY: The head of Turkey’s Information and Communication Technologies Authority, or BTK, says the country’s cybersecurity center is continuing operations against the malicious software.

FRANCE: French carmaker Renault’s assembly plant in Slovenia halted production after it was targeted.

BRAZIL: The South American nation’s social security system had to disconnect its computers and cancel public access. The state-owned oil company Petrobras and Brazil’s Foreign Ministry also disconnected computers as a precautionary measure, and court systems went down.

SPAIN: The attack hit Spain’s Telefonica, a global broadband and telecommunications company.