Microsoft says it estimates that 8.5 million computers around the world were disabled by the global IT outage on Jul. 19. The glitch, which brought many computer systems and businesses to a screeching halt, came from CrowdStrike who sent out a corrupted software update to its huge base of customers. The number given by Microsoft means it is probably the largest ever cyber-event, eclipsing all previous hacks and outages. The closest to this is the WannaCry cyber-attack in 2017 that is estimated to have impacted around 300,000 computers in 150 countries. "We know that adversaries and bad actors will try to exploit events like this," David Weston, Vice President, Enterprise and OS Security at Microsoft, said in a blog post.