Tips to prevent system hijacking

The attack is not new: It's known as a "passing-the-hash" attack, and it's been around for years. Those proficient in security matters know of the attack and the general principle behind it: Passwords are converted by Windows into a "hash" -- a fixed-size string of cryptographically transformed data -- every time they are created. This way, your passwords aren't sitting in plain text anywhere on your machine, nor are they transmitted in clear text when the authentication happens over the wire.
 

When authentication does need to happen against one resource or another, Windows hashes the password you provide and then submits that hash to the host. The host then compares it with the hash it has on record; if it's the same, you're granted access; if not, you're turned away, of course.
 

But what if you were able to access the hash database for privileged accounts -- for, say, an administrator -- and pass that hash directly to a resource? Remember, Windows never transmits the passwords themselves. The only computation that is done is matching the transmitted hash to a hash that's stored in a database of valid authentication data. If you connect and pass an administrative username and an administrator's hash, that's all you need to gain privileged access to a system. You don't need to know the password; you just need the hash.
 

So what's the problem here?