Washington/London, May 14 (PTI): Nearly 100 countries, including India, were hit by what is believed to be the biggest-ever recorded cyberattack.

“Cyber weapons” stolen from the US’ National Security Agency were used to lock up computers and hold users’ files for ransom.

The cyber attack was first reported from Sweden, Britain and France, US media said. Security researchers with Kaspersky Lab have recorded more than 45,000 attacks in 99 countries, including the UK, Russia, Ukraine, India, China, Italy and Egypt.

An increase in activity of the malware was noticed on Friday, security software company Avast reported, adding that it “quickly escalated into a massive spreading”.

Within hours, over 75,000 attacks were detected worldwide, the company said. Meanwhile, the MalwareTech tracker detected over 1,00,000 infected systems over the past 24 hours.

Alert in India

The Centre on Saturday issued a security alert to computer users following a wave of cyberattacks across the globe, including over 100 computers of the Andhra Pradesh Police.