A botnet is a connected network of malware-infected computers which are controlled by cyber criminals and used to commit cyber crime.
Users have their computers taken over after being infected with a Trojan or other type of malware.
The cyber criminal responsible can then organise these infected machines into a network of ‘bots’ that the criminal can manage remotely. Bots more broadly are software applications that run automated tasks over the internet. They perform simple and repetitive tasks much quicker than a human could.