I've worked at a large company similar to Boeing. Our IT providers are the same (CSC). Backups are regimented and any virus activity is dealt via, as the tweet

I've worked at a large company similar to Boeing. Our IT providers are the same (CSC). Backups are regimented and any virus activity is dealt via, as the tweet puts it, remediation. If a computer is detected as having a virus/suspicious activity, etc, it is carted off immediately and wiped (they possibly do forensics, dunno). The system is reimaged, backups are checked and restored.