Do you have any addon installed in your browser like that ? Most probably that is not from addons.mozilla.org. It may be any infected plug-ins /extension which stored there. AFAIK when any dev submitted there developed extension , reviewer team will do a check for there trusted functionality,so you always will get a remove button with that.

And once you removed it from there it will uninstall completely . However such suspicious things still appeared in your system even after uninstalling it from addons section.

My comments about how to find that extension on disk are in your other thread: https://support.mozilla.org/questions/1085454

Extensions that do not have a "Remove" button are installed by other software and are not under control of the Firefox extension manager. Such globally installed extensions are usually found via a registry scan or are installed in a location that Firefox scans for installed extensions.

• https://developer.mozilla.org/Installing_extensions
• https://developer.mozilla.org/Adding_Extensions_using_the_Windows_Registry

Extensions installed this way need to be removed via the settings (options/preferences) of the program that has added this extension or this program has to be uninstalled via "Control Panel > Programs". In Firefox you an only disable such an extension.

Hello jscher2000 and Chandan_Baba,

thank you for your message. Meantime I have found a solution, how to remove and to delete addons from registry and from mozilla firefox profiles folder.

pemigabo123