What are these Windows processes on Linux?

Some Windows apps running in Wine or front-ends to Wine like PlayOnLinux or Crossover leave explorer.exe and other Windows executables open after they are closed. Try running some of your Wine applications one by one and check in htop for explorer.exe after you close them.

Or run this command in the terminal:

ps -aux | grep "explorer.exe\|services.exe"

The two Windows processes in your question have been running for more than 8 hours. Possibly they have been running since right after Ubuntu booted. Kill the PIDs of explorer.exe and services.exe and check if these two processes come back afterwards. To kill the PIDs of explorer.exe and services.exe in the example in your question use this command:

kill 3413 3110  

The results of running the above command showed that the two Windows processes have been running since startup. Open the built-in Startup Applications app which shows a list of all Additional startup programs in your operating system.

Startup Applications showed only a normal Ubuntu startup program in the list of additional startup programs. Run the following command right after the next time you start up Ubuntu to show what process forked what so you may get a better idea what process is calling your two Windows processes.

ps auxf

Look at the /proc filesystem:

ls -l /proc/3413/exe

And it will show you the binary of the process. Under the directory, there are more pseudofiles giving useful information, and another useful one is cmd,

cat /proc/3413/cmd

giving you the arguments used to launch the process (if any).