Strange moveable tile appeared on desktop

[#1]

I shut off my laptop last night with no issues. I yurned it on today and after about 5 minutes, a little grey tile appeared in the bottom right of the screen.


The tile can be moved around the desktop by right clicking and dragging. There are no properties to it and you can't double click it.
I am a careful surfer and I use Chrome as my broweser. I have Comodo running and have scanned the laptop. I have also used Spybot, Malwarebytes and Ccleaner to give it a good going over. I have looked in the processes box and can't find anything relevant and I have also checked all the startup entries to no avail. Finally there was a system restore to 4 days ago.
Anyone got any ideas what it may be as I don't even know what to Google for?
Thanks
Mark

[#2]

To help identify which process has created the window,  you can use Process Explorer.
Click and Drag the icon that to the right of the binoculars over the errant window,  process explorer should then highlight the owning process in its list.

[#3]

Thanks for that, I will keep that for further use. I found a (hopeful) solution which was to right click and alt F. Hopefully that is the end of it 
Mark

[#4]

Bet you're using Comodo.
Check here -
https://forums.comodo.com/install-setup-configuration-help-cis/invisible-prompt-merged-t109367.45.ht...

[#5]

Quote from: Marksfish

I have Comodo running and have scanned the laptop.

I bet this gave it away 
Thanks for the link. I am happier now I know that I am not the only one suffering from this whatever it is.
Cheers
Mark

[#6]

Ha ha!
Just saw that strange C image on a post on the Comodo forums and thought, hang on, where have I seen that before?

[#7]

It was spot on and just the answer I was looking for thanks. You da man