Insider threat is the most likely system vulnerability in a company that deploys antivirus, anti-malware, and firewalls that can be assumed to be functioning properly. An insider threat is a malicious or negligent act by an authorized user of a system or network that compromises the security or integrity of the system or network. An insider threat can include data theft, sabotage, espionage, fraud, or other types of attacks. Antivirus, anti-malware, and firewalls are security tools that can protect a system or network from external threats, such as viruses, worms, ransomware, or open ports. However, these tools cannot prevent an insider threat from exploiting their access privileges or credentials to harm the system or network.