Reducing risks when using untrusted computers

Install Tails from a computer that you trust

Tails protects you from viruses and malware on your usual operating system. This is because Tails runs independently from other operating systems.

But your Tails might be corrupted if you install from a compromised operating system. To reduce that risk:

  • Always install Tails from a trusted operating system. For example, download Tails on a computer without viruses or clone Tails from a trusted friend.

  • Do not plug your Tails USB stick while another operating system is running on the computer.

  • Use your Tails USB stick only to run Tails. Do not use your Tails USB stick to transfer files to or from another operating system.

If you worry that your Tails might be corrupted, do a manual upgrade from a trusted operating system.

We don't know of any virus able to infect a Tails installation, but one could be created in the future.

No operating system can protect against hardware alterations

Your computer might be compromised if its physical components have been altered. For example, if a keylogger has been physically installed on your computer, your passwords, personal information, and other data typed on your keyboard could be stored and accessed by someone else, even if you are using Tails.

Try to keep your computer in a safe location. Hardware alterations are more likely on public computers, in internet cafés or libraries, and on desktop computers, where a device is easier to hide.

If you worry that a computer might be modified:

  • Use a password manager to paste saved passwords. This way, you don't have to type passwords that might be visible to people or cameras near you.

  • Use the Screen Keyboard, if you are using a public computer or worry that the computer might have a keylogger.

Keyloggers are easy to buy and hide on desktop computers but not on laptops. For an example, see KeeLog: KeyGrabber forensic keylogger getting started.

Other hardware alterations are much more complicated and expensive to install. For an example, see Ars Technica: Photos of an NSA “upgrade” factory show Cisco router getting implant.

No operating system can protect against BIOS and firmware attacks

Firmware includes the BIOS or UEFI and other software stored in electronic chips on the computer. All operating systems, including Tails, depend on firmware to start and run, so no operating system can protect against a firmware attack. In the same way that a car depends on the quality of the road it is driving on, operating systems depend on their firmware.

Keeping your computer in a safe location can protect against some firmware attacks, but some other firmware attacks can be performed remotely.

Firmware attacks have been demonstrated, but are complicated and expensive to perform. We don't know of any actual use against Tails users. For an example, see LegbaCore: Stealing GPG keys/emails in Tails via remote firmware infection.