Tor network is known to have malicious exit nodes. CISA specifically recommends to fight against this issue by outright blocking all tor traffic https://www.cisa.gov/sites/default/files/publications/AA20-183A_Defending_Against_Malicious_Cyber_Activity_Originating_from_Tor_S508C.pdf
This made me think. What safeguards Qubes has? Example of the the attack scenario: A regular tor exit nodes turns malicious. Either by being hacked or by threat actor deliberately introducing it into the system. Then it looks for requests towards Debian/Fedora/Qubes specific repositories. Once such requests happens it serves the victim’s machine to use fake copy of repositories with maliciously modified binaries. After the upgrade is finished there is no easy way to know whether or not the upgrade was malicious. Depending on what was upgraded the infection might be limited to certain templates or to dom0
I can see at least 2 scenarios in which such attack can be useful. Qubes users are notoriously paranoid compared to regular linux users. And the OS requires way more ram compared to average linux distro. It’s safe to assume any Qubes user is either somewhat richer then average person or has a lot to hide. Financial incentive is quite strong. The second scenario is intelligence agencies trying to find one particular person. Snowden recommends Qubes as a daily driver. If he configured his system to use sys-whonix as update proxy it’s reasonable to assume the agencies could try to perform such attack. With a lot of people getting hacked as a side effect. In fact any state actor might be interested in performing such attack if one valuable target is daily driving Qubes