There is no such thing as a Denial of Service (DoS) attack more sophisticated than one that can be launched by somebody in their basement.
The "sophisticated" cyber attack is a cliche, a trope, used to disguise the victim's own ineptness. It's not us that is so stupid, but them that is so sophistimicated.
For example, one of the least sophisticated things hackers do is PsExec to spread from one Windows machine to another. This has the effect such that once they get a foothold into a Windows network, they can spread throughout the rest of the network.
There are a bunch of simple things that can be done to stop or limit this, such as removing local admin privileges and segmenting active directory domains. A lot of state and local government's won't do this, so remain vulnerable to this unsophisticated attack.
There are organizations that keep up, changing their networks as cyberthreats change.
Then there are organizations chronically behind the curve, refusing to change until the pain forces them.
Then there are organizations chronically behind the curve, refusing to change until the pain forces them.
