What is a cyber attack? As NHS declares ‘critical incident’ and cancels operations, how hackers exploit ‘flaws’ in systems to seize control

The NHS declared a critical incident after a ransomware attack on lab services provider Synnovis led to cancellations of operations and blood tests across London hospitals. The attack, which caused significant disruption of services, resulted in hospitals having to cancel or outsource procedures. Cybersecurity experts warn that specialist brokers and ransomware gangs might have exploited simple flaws to seize control of vital health services data for profit. To restore services, Synnovis must pay the ransom or restore its data, a difficult and cumbersome process that can take up to weeks.