Kingdom Extension is a new nasty program. The adware is a very intrusive software. It may attack all popular web browsers today. Note, the program may be installed without your permission. Thus, you should pay more attention while installing a new program. You must read the EULAs. If you detect any suspicious or unknown apps, you should switch the Custom installation mode and deselect them. Otherwise, Kingdom Extension adware will be installed. Then, the program will monitor your web browsers, history, habbits, so on.