IT Security is often the last thing new enterpeneurs think about.  It doesn't make you more efficient and when it's working well, it should be nearly invisible. In an always connected world, hackers and malware (viruses, spyware, ransomware) are a constant threat.  Your first defence is a good, commercial grade firewall. It will detect and prevent malicious traffic from entering your office network.  Secondly, each endpoint (server, desktop/laptop, mobile device) needs their own security software (firewalls, antivirus). Thirdly, every employee needs adequate training to identify security threats before clicking that malicious link.