It would be interesting to know how quickly an unprotected computer would succumb to a virus these days. The only sources I found are quite old - from 2005[0] (20 minutes) and 2007[1] (8 seconds!).

[0]https://www.cbc.ca/news2/background/computer-security/

[1]https://www.informationweek.com/cyber-resilience/how-long-do...