Malware

Malware (malicious software) is any program installed on a device without the owner's meaningful consent that acts against their interests. It reaches devices through phishing email attachments, malicious websites, infected USB drives, fake software downloads, or malvertising (malicious adverts on legitimate sites).

The consequences of malware infection range from annoying (unwanted adverts) to catastrophic (complete data encryption and ransom demand, or silent credential theft). Many malware strains have multiple payloads — they may install a keylogger to steal passwords, a RAT to give the attacker remote control, and a module to spread to other machines on the network.

Antivirus software helps but is not sufficient alone. Safe browsing habits, keeping software updated, and not opening unexpected attachments remain the most effective defences.