Please consider the following setup:

A computer running a non-deprecated and up-to-date version of Windows (e.g. 7/8/10) is physically connected to a LAN or WAN network by means of a plugged-in network cable. The network adapter for this particular physical connection has been deactivated in Windows's Control Panel.

Wireless functionality, if installed in the computer, has been turned off on a low level (e.g. in BIOS/UEFI). Sharing and Remote Desktop functionality have been turned off, too. The Windows firewall is enabled. Default Internet Options are applied. There is no other security-related software installed.

Windows is idling. Sleep mode and hibernation have been turned off. No additional devices are or have ever been plugged in the computer (not including inconspicuous KVM) nor have there been done any changes to the software apart from installing the latest OS updates and original computer drivers downloaded from the Internet which was the only occasion of ever having been connected to a network before. (Power and physical access is not a concern. Sensitive data of any security level is or was never present.)

How difficult is it and by what means is or would it be possible to access such a computer from LAN or WAN and conversely, how "secure" is this setup?

Thanks for your input!

  • what book did this question come from? – schroeder Jul 11 '17 at 21:06
  • "The network adapter for this particular physical connection has been deactivated" .... this is as secure as it gets while still being powered on – schroeder Jul 11 '17 at 21:08
  • What I'm trying to figure out is if it is generally possible to circumvent even this setup, which I also think is fairly secure, and so to say push the boundaries of the barring constraints imposed by the software while merely using the electric connection as the only available opportunity for an attack — I did not find this question somewhere. I came up with that myself. – 126047281 Jul 11 '17 at 22:07
  • There have been attacks that use computer speakers and microphones to send and receive data using ultrasonic chirps, but this would require a second network-connected PC nearby and malicious software somehow getting on the target PC. – David Jul 11 '17 at 22:07
  • @126047281 If you're talking about attackers with many resources you might want to think more generally about side-channel attacks: en.wikipedia.org/wiki/Side-channel_attack . Can you capture the screen with a camera? Can I send an agent to install a hardware bug in the keyboard that allows me to read or insert character streams remotely? Can I monitor the computer's power consumption? Can I get Microsoft to install a backdoor for me? Do I have a double agent who has physical access to the computer? – David Jul 11 '17 at 22:11

What you're referring to is known as an air gap.

While you'd think a computer with no physical connection would be completely secure, there is at least one attack that gets around it!

Oh wait, here is another.

And yet another.

These are pretty bizarre attacks (someone seems to have a lot of time on their hands), but you did ask. If you google around for air gap attacks I'm sure there will be more.

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