Ok, so you use this setup exclusively at home ... not for gigs, right?
First of all, try to find the cause of the problem systematically (by exclusion).
1. Connect headphones to the Soundcraft to check if the hum is still there after every step below
2. Disconnect the XLR Main Outs of the Soundcraft
3. Turn down ALL Level knobs of unused channels on the Soundcraft (like 3, 4, 7/8, 9/10, 11/12)
4. Disconnect the microphone
5. Disconnect USB
6. Disconnect the TS cables coming from your Profiler
At some point the hum should be gone. If it's gone only after step 6, you will likely have to hook up your Profiler through a balanced connection
(XLR female ->TRS cables from Profiler Main Outs). If the hum is gone at a different step ... e.g. after disconnecting USB, let us know.
One of the potential issues is that your Profiler is grounded, your PA speakers are grounded as well and your computer (USB connection) might be grounded as well ... but the Soundcraft isn't because it doesn't have a 3-pin plug.