Malware (malicious software) is any program designed to damage, disrupt, or gain unauthorized access to computer systems. Types include viruses that spread between files, ransomware that encrypts data and demands payment, spyware that secretly collects information, and trojans that disguise harmful functions as legitimate software. Municipal governments are frequent targets for malware attacks, with ransomware incidents having disrupted city services across North America. Protecting against malware requires updated antivirus software, regular security patches, employee training to recognize phishing attempts, and backup systems to recover from attacks. Cybersecurity has become essential to protecting municipal operations and citizen data.