Abusing Windows' ability to obtain HW-drivers though UEFI (something which can be used for good) to bundle shit-ware is just absolutely rotten.
Edit: As pointed out by josteink, the BIOS wasn't backdoored - it was used to install a backdoor. But calling what it installed "insecure Windows-software" is also inaccurate. According to https://en.wikipedia.org/wiki/Superfish#Lenovo_security_inci..., its purpose was man-in-the-middle attacks against the user. So I still think criminal liability and jail time would be just. Ordinary people have been sent to jail for far less.
The BIOS itself was fine, but it contained insecure Windows-software which it requested/instructed Windows to install.
Install any other OS (like Linux) and there would be no backdoor at all.
To be clear I’m not trying to defend Lenovo’s actions here, I’m just trying to be clear about what this incident was actually about. The simplistic description is IMO a bit too simplistic in this case.
That would be up to a prosecutor. A civil suit would take the form of a class action.
I think it would be perfectly fair for Microsoft to require OEM licensees to not use that feature for shitware installations. I can't see how that would fall afoul of antitrust or related regulations. Maybe I'm wrong though, that was a while ago and it wasn't my specialty when I practiced law.