Experience Note When organizations suffer a successful social engineering attack, it makes banner headlines. Employee training and compliance auditing will help in avoiding these disasters.
Auditors and senior managers must be mindful that attackers are employing these tactics, so using them in a measured fashion has great benefits in probing vulnerabilities. In essence, social engineering involves getting employees to voluntarily surrender information that can be used to gain an advantage that would not be available without it. It can be as easy as a telephone conversation, going through someone's wastepaper basket, or using an unprotected workstation.
The primary tool of the social engineer is the telephone. Typically, a talented auditor can obtain more critical information and cause greater damage by working making a few telephone calls than the best network attacker. Among the most common approaches are:
Experience Note One of the most interesting, inventive, and legendary social engineering activities was the new maintenance employee who was seen posting small signs around an office area. These signs announced a new telephone number for the company's technical support unit. When one of the senior managers asked the employee who it was that requested he post the signs, she responded that she was new and did not know the person who asked. The manager did not follow it up any further. After about a week, the company's technical support staff sent an e-mail to their manager asking what happened to all their calls. They had not received a trouble call in several days. It was discovered that when calls were made to the "new" telephone number for the technical support unit, a recorded message stated that all agents were busy; and requested the caller to verify his identity with network logon name and password. It was discovered that the callers' network accounts had been accessed and sensitive information taken through terminals located inside the company during off-duty hours. Additionally, the organization had not verified the identity and background of the maintenance person.
If the rules of engagement permit, auditor's can use social engineering for gaining access to the company's systems. For example, an auditor, not previously introduced to the target organization arrives early at the organization and loiters near the entrance. When an employee passes security and enters the office space, the auditor, acting as a new employee, offers the excuse they are new and have forgotten their identification badge, and follows the employee inside. Or an auditor telephones the network administrator and misrepresents himself as a member of the management staff and asks the administrator for her e-mail account password to be reset. The administrator provides a one-time use password without verifying the caller's identity and the auditor accesses the manager's e-mail account. Should such tactics be allowed? If the audit is going to test the risk management training provided to the employees, the answer is yes. Regardless, the use of social engineering tests must be addressed in the rules of engagement. If auditors do not test the system's vulnerabilities, attackers will. Again, it is not a matter of if an attacker attempts this type of intrusion; it is only a matter of when.
Senior managers and auditors must arrive at a level of understanding of whether the employees are going to be advised of the system testing or not. If employees are aware of system testing, they will likely be on guard and on their best behavior. However, if the rules of engagement allow the auditors to fully explore and exploit if the system crashes due to an attack, the administrators can take appropriate action without panic. But, not advising employees has advantages, in that auditors will observe the true performance of how employees react to system attacks and how recovery efforts are brought to pass. Obviously, telling or not telling employees of the system assessment is a matter for careful consideration by senior managers with the matter fully documented in the rules of engagement. Safeguards are typically deployed in the event of electing not to notify employees to avoid having embarrassing calls made to law enforcement.
The last area of preparation includes the area of permission. Appropriate levels of permission must be obtained before conducting this type of system vulnerability assessment. This is an area of good judgment. Auditors must do a thorough job, but they cannot damage any critical assets in any fashion including employee morale. On the other hand, the more realistic these tests are, the more useful will be their results. Use good judgment in crafting the rules of engagement and obtaining the appropriate levels of permission.
