Malware

Malware, short for malicious software, is any program or code designed to perform harmful actions on a computer system, network, or device without the user's informed consent. It is used to steal data, disrupt operations, gain unauthorized access, or cause other damage.

Common forms include viruses, worms, trojans, ransomware, spyware, adware, rootkits, backdoors, and botnets. Some malware replicates or spreads on its own, while other samples rely on tricking users into installing them or exploiting software flaws.

Malware pursues varied goals, from financial theft and espionage to sabotage and the creation of networks of compromised devices. The consequences can include data loss, encryption of files, system downtime, and costs for remediation and lost productivity.

Attack vectors include phishing emails, malicious links or attachments, compromised websites, drive-by downloads, removable media, and supply-chain compromises. Security software and best practices help reduce risk.

Defenses include keeping software up to date, using antivirus or endpoint protection, firewalls, strong access controls, regular data backups, and user education. Response to an infection involves identifying affected systems, removing malware, patching vulnerabilities, and monitoring for residual threats.

The history of malware dates to the early days of personal computing, with evolving families and techniques over time. Notable incidents such as ransomware outbreaks and large-scale intrusion campaigns have underscored the ongoing need for proactive defense and rapid incident response.