> Shame they deleted the scene explaining all that. It's still easy to find though.

Huh! I always thought the logic was that since the aliens used earth satellite systems they had already interfaced with human computer systems and the infection was made via the satellite system, which I believe the main character was knowledgable about.

That doesn't entirely follow, though. Just because you could talk to the alien computers doesn't mean you could execute a program on them. IMO the deleted scene is the only way it can make sense.

Put differently: you can’t run a windows/linux exploit on a Linux/windows machine just because they can both connect to the Internet.

This. But everyones focused on languages lol.

Actually lol, who says the aliens were not running a emulator of our own systems and in their hubris ran it on elevated privs.

ok ok, considering the Aliens allowed their own ship, which was visually compromised AND could have been easily scanned for non-alien life(?)... clearly not a culture of security.