After an attacker has performed scanning and recon, gaining access is the next step. The vast majority of hacks involve gaining unauthorized access to accounts or systems. There are many ways for attackers to gain access, and not just through hacking. In recent years, social engineering has been the number one way that attackers gain unauthorized access to systems, usually through phishing emails. However, malware such as viruses, worms, and trojans can all be used to gain an attacker entrance to computer systems.