Developed by Hampshire-based Gamma International, software known as 'Finfisher' was installed unknowingly by users in at least 36 countries, misrepresenting itself as a programme named Firefox.exe, identical to the programme name of the Firefox internet browser. Finfisher can grab stills of computer screens, record keystrokes and Skype chats, and remotely switch on cameras to film users at work, but does not infect the broswer itself. Mozilla announced yesterday it had sent a cease and desist letter to Gamma International, "demanding that these illegal practices stop immediately" and referring to the use of Firefox's brand and trademarks to trick users into downloading Finfisher as "abuse".