david.emery writes: MacOS and iPhones that haven't been jailbroken fare pretty well (although vulnerabilities exist, there's not been a lot of exploitation). Apple does come in for criticism for 'time to fix' known vulnerabilities. Jailbroken iPhones are a mess. The biggest risk to Macs are Trojan Horses, often from pirated software. Link to Original Source
Thus spake the master programmer:
"When a program is being tested, it is too late to make design changes."
-- Geoffrey James, "The Tao of Programming"