Ok if you do as i suggest first then you will know for sure if it’s IN cubase, which, unless it’s a plugin is highly unlikely.
If it’s not a plugin then it’s likely to be something electrical/RF related and the most likely way you’re going to track it down is by doing things a step at a time methodically, not by making assumptions that the problem is in cubase before even checking as i’ve suggested to actually verify that.
Try exporting a file using cubases’ tone generator, try a slow sine wave sweep with no processing, also try exporting a blank region of time in cubase, a minute or so, that way if cubase is generating the noise you will hear it on its own… the files exported from cubase are generated entirely within cubase, unless you’re using external sound sources or external processors so the resultant files won’t have passed through any of your computer hardware, only cubase if you follow?
If, as i suspect those files are noiseless, which will indicate whether or not cubase is the cause of your issue, then start reintroducing things one at a time and keep an ear out for the noise again.
If you work through things in this way you’re much more likely to find the source of, and be able to remedy your issue quickly.
Also there’s no such thing as ‘USB noise’… if USB devices are causing noise then there’s an electrical/RF issue in your system…