Antivirus software
Most tests and experts claim that while antivirus software is extremely useful in preventing some cyber attacks, but it is unable to all attacks. That is because once a piece of malware has been identified, hackers know that this malware will be added to the list of already-known viruses, and it will no longer be able to pass through most signature-based detection systems. Also, antivirus software is not completely perfect, and there are more new and emerging threats that mostly sneak by a computer's defenses.