Co-authored by Quinn North, Senior Incident Response Analyst, IBM Security.

Previously, we discussed the use of the feedback loop to help educate end users on how to improve secure computing practices. Here, we will discuss the feedback loop’s merits when applied to a regular part of an organization’s user auditing.

Weak Passwords Make for Weak Networks

End user auditing consists of ensuring security policies — such as password requirements — and due care is provided to sensitive documents.

Clients regularly ask IBM’s X-Force Incident Response team to scan their networks for intrusions, malicious activities or other risk factors. One such risk factor that we look for is the use of weak passwords. As countless security compromises have shown, weak passwords are a common root cause for the initial breach of a victim network.

Consider the results from three recent threat assessments where the clients asked us to examine the strengths of their passwords:

• Of 3,000 user accounts scanned, 643 passwords were cracked (21 percent).
• Of 10,777 user accounts scanned, 1,859 passwords were cracked (17 percent).
• Of 3,086 user accounts scanned, 469 passwords were cracked (15 percent).

None of these user accounts were cracked over a period of weeks using a supercomputer with specialized software; all were cracked within 30 minutes on a generic laptop using free software.

Applying the Feedback Loop

One of the aforementioned organizations wisely decided to get serious about weak passwords within its environment after being presented with these findings. In addition to embracing technical controls that required strong passwords (e.g., passwords with minimum characters, numbers, special characters, etc.), the client also periodically attempted to crack its own passwords to identify weak ones that may still meet the complexity requirements. For example, [email protected], while it contains letters, numbers and a symbol, is still easy to guess since attackers would likely include it within a dictionary list used to crack passwords.

Using the four stages of the feedback loop, the client embarked on an aggressive campaign to suss out any deficient and risk-inducing passwords:

1. Once a week, the organization collected the password hashes (which are required to crack a password) from the user accounts within its network.
2. After applying a moderate level of effort to crack the passwords, the client discovered that approximately 20 percent of the passwords were still far too easy to crack.
3. The employees with the easily crackable passwords didn’t receive a simple email stating their password was deficient. Rather, they were counseled on how their password was cracked with ease, educated on how to develop a secure password and asked to change their password. The interaction was personal and ensured that the message resonated with the employee.
4. The client continued the process once every week and remeasured the behavior until the percentage of crackable passwords was reduced to the low single digits.

While some manpower is required to perform weekly gatherings of password hashes, this was essential to ensure that newly changed passwords were promptly gathered and recorded. Then users could be educated on their actions before too much time had elapsed.

Don’t Forget Service Accounts

These same methods should also be applied to service accounts, which are accounts that perform application functions with no user interaction. These accounts typically have elevated privileges to complete administrative tasks and are always an attractive target to attackers.

Often the default passwords are not changed or are changed to something that can be easily cracked. Additionally, some of these accounts may have been created prior to the adoption of a more stringent password policy and are thus grandfathered in with weak passwords. These accounts should not be overlooked during your password audit. However, because they are typically tied to running applications in a production environment, care should be taken when attempting to change them.

Regular auditing of user passwords while leveraging the feedback loop is a low-cost method to ensure end users don’t unintentionally introduce risk to your environment. It also helps develop a culture of security awareness and provide quantifiable data demonstrating improvement in security best practices over time.

Applying the feedback loop only helps to strengthen security and password initiatives. End users, when presented with timely information to correct their behavior, will serve as a force multiplier to your security posture.