PUP.Optional.MyPCBackup is the detection name for MyPC Backup, a Potentially Unwanted Program (PUP) that is an online backup solution marketed by JDI Backup. It stands out from their other products because it is often included in bundles, and you will see advertisements for it in almost every corner of the Internet.
They do actually provide a backup solution, but it is not customer-friendly and expensive compared to other such services.
Common infection methods
There are two common methods of infection: either users install the trial of the product themselves, or the product gets bundled with other software. In both cases, the trial will keep reminding users to register and buy the product.
Both the trial version and the full product can be fully removed by using a full Threat Scan with Malwarebytes Anti-Malware. A removal guide can be found on our forums here.
A full Threat Scan should get rid of all the files and associated registry keys. If you have registered the product, you may get some spam on the address you used. Unsubscribing from the email list might help stop that.