Malware, or malicious software, is any program or file that is designed to compromise a computer or network. Malware includes many varieties of computer viruses, worms, Trojan horses, spyware, and adware, and it has become both plentiful and sophisticated. Malware is coded to perform a range of functions, including stealing, encrypting, or deleting sensitive data; altering or hijacking core computing functions; and monitoring users’ computer activity without their permission.