Wow, multi-year is truly embarrassing. Hosts being compromised is the the worst case scenario because the attacker can decide who to serve the malware to in a spearphishing fashion.
It happens to more companies than you'd imagine, even big ones. Security monitoring and logging is hard to get right, especially if you try to add it to a previously insecure system.
A smart attacker can hack your company unnoticed and passively watch your company for the right moment to strike. I doubt that the hackers logged into the office VPN every day.
A smart attacker can hack your company unnoticed and passively watch your company for the right moment to strike. I doubt that the hackers logged into the office VPN every day.