
Someone earlier mentioned group policies as a way to improve security...
Group policies are fundamentally flawed in their implementation...
Let's bring up the example of the policy which is supposed to prevent you from opening a command prompt.
So you run cmd.exe, and it pops up a message saying your not allowed to do that...
Now in any sensible implementation, it would be the OS which is doing that... But that's simply not the case.
The cmd.exe program itself executes, and within the program itself checks for the presence of a registry key forbidding cmd.exe use, if it finds it then it displays the message and exits. So the OS does nothing to stop you executing the program, the program does its own check.
So what if you run a different command interpreter, say command.com? Yes, that still works, since they didn't implement the same check into command.com.
And if you have the ability to introduce your own binaries, which you almost certainly do, then you can simply execute a modified cmd.exe that has the check removed (very simple with a hex editor, just change the registry key it looks for so it wont be found).
Also, cmd.exe will still let you execute batch files regardless...
And then there's regedit/regedt that will exit, but reg.exe from the commandline will still work, and you could just supply your own regedit.
Same with restrictions on browsing drives, supply your own apps and they bypass the half assed restrictions.
And when it comes to users supplying their own binaries, on a unix machine you would mount all the areas a user could potentially write to (including removable media) with the noexec flag, windows has no equivalent of this and you need to implement third party binary whitelisting...
Now specifically to the mytob worm, this spreads by exploiting the LSASS vulnerability i believe, and the systems were clearly not patched against it. Surely it would have been more sensible, on workstations at the very least, to disable any listening network services... There really is no need for these services to be available to the network, and if you turn them all off even an un-patched machine won't become infected.
Ofcourse the stupid thing is that such complex bloated services ship enabled by default on a workstation OS.