The unlocker installs a background process that uses your CPU/GPU to mine Monero. Your Cubase will lag, your PC will overheat, and your electricity bill rises. You will never see the miner – it hides as svchost.exe or a Windows service.
If you ran an steinberg activation manager unlocker install.exe file and now suspect malware: steinberg activation manager unlocker install
Do not try to "repair" by downloading more unlockers or registry cleaners. That compounds the damage. Launch the Activation Manager and sign in with