Malware is a collective term for malicious software created to disrupt normal computer operations, gather sensitive information, gain unauthorised access to systems or display unwanted advertising. It includes viruses which attach to other files to spread, worms that replicate across networks, programmes known as trojans that disguise themselves as legitimate software, ransomware which encrypts files until a ransom is paid, spyware that monitors user activity and adware that shows unsolicited adverts. Malware can enter devices via email attachments, infected websites or by downloading untrusted files. Protecting against malware relies on keeping software up to date, using reputable security tools and avoiding suspicious links or downloads.
