They’re probably talking about the BMG rootkit from the 2000’s. Basically, when you inserted a Sony CD into your computer, it would automatically and silently install a rootkit on your PC, which introduced a backdoor on your PC that was being actively exploited. It was also notoriously difficult to remove, as it would reinstall itself even if you deleted every visible trace of it.

Then when shit hit the fan and Sony was making headlines for it, they released a “fix” for it. The fix didn’t actually remove the rootkit, and simply hid files with specific names (the rootkit files) from the users. This only introduced another vulnerability, where hackers could just name any virus the same as the rootkit, and it would automatically be hidden.

All in the name of DRM. The rootkit was initially meant to stop you from ripping and copying the CD.