I have been reading for about an hour and searching for the stock RUU. Before I forget, I'm running OMNI ROM on android 4.4.2 and have CWM recovery installed.
Anyways back to topic. I couldn't find any RUU's for my device but read on here that you can restore using a nandroid backup if you can find one. Now me and my brother both got an HTC One at the same time but I went through so many ROMs and customizing it. I started with CWM and made a back up of the stock rom but kept getting errors with some ROMs so switched to TWRP and couldn't use it anymore. With android 4.4 I needed to go back to CWM but in some point when tesering ROMs I only had 3GB free of space so did a wipe and fresh install so I don't think that the original back up is still there somewhere.
Anyways. I have my brothers HTC One here and that's stock. Nothing modified what so ever. Can I make a nandroid back up or use a tool to extract the firmware from his phone and somehow use it to restore my phone back to stock, unroot, relock boot loader and get rid of the *tampered* flag in fast boot?
The phones still on contract, only had it for like 4 months and thinking of giving it back and getting an upgrade to the One Max or when the One 2 comes out but I don't think Virgin mobile will allow me to since the phones been tampered with.