Reviving this old thread, due to the appearance of the same "default.profraw" file on an iMac running Mojave 10.14.6.
It seems to be generated after any reboot, and running Disk Warrior (DW). I have never installed CleanMy Mac on this system. I have seen it on the root level of my normal boot disk and the target disk after cloning the source disk and then rebooting from the target disk, and also after running DW. I have also seen it on a High Sierra system, but much less often.
Does anyone have any real idea what is causing this?
In regard to the "default.profraw" file, I asked the programmer of a major backup application; Saying ... "I can only assume it is the result of some programming error caused by something I have installed." His reply;
"default.profraw: LLVM raw profile data, version 4"
Some other application must have "LLVM Code Coverage" (a feature offered in Xcode) enabled for their release build.
Now I suspect either cDock or Disk Warrior could be using that coding option.