A large school district approached Red Sentry based on a recommendation, looking for a fresh perspective on its annual cybersecurity testing. Having completed penetration testing in the past, the district’s leadership felt confident in its security measures; it had even strictly followed Microsoft security guidelines and received a clean bill of health in the previous year's assessment.
But the stakes were high.
As a district managing over a dozen schools, its network contained sensitive student and staff data, including records for thousands of children and adults. Here are a few examples:
A single vulnerability could lead to a devastating data breach, putting the district at risk of serious school cybersecurity threats.
To uncover potential risks, Red Sentry conducted an internal network penetration test designed to simulate a real-world cyberattack. The test examined what could happen if a hacker or insider thread gained access to just one device within the school district’s network—a scenario that could easily occur due to a disgruntled staff member, unattended device, or compromised system.
Red Sentry used a Grey Box penetration testing approach using ethical hackers to assess how much damage could be done. The goal was to determine how exposed the district’s sensitive student and staff data was, and how quickly a threat actor could escalate access to take over the entire system.
This pentest proved that protecting student data should be a top priority, and the district’s cybersecurity defenses needed improvement.
Red Sentry’s internal penetration test unfolded over several rapid stages. By simulating the actions of an attacker within a school environment, the test uncovered major vulnerabilities that could have led to a catastrophic data breach. Here’s a breakdown of how the pentest went:
The team gained its authorized starting point within the internal network by using a Dropbox device provided by Red Sentry. This device mimicked an internal attacker’s starting point and only needed to be plugged into an open network jack.
Red Sentry began its school network security audit with a full scan and quickly identified a Common Vulnerabilities and Exposures (CVE) issue in one of the district's printers. This vulnerability allowed them to ‘dump’ the printer's address book and extract stored credentials.
With these stolen credentials, Red Sentry launched a controlled password spraying attack and successfully logged into a low-privilege user account.
Through this initial foothold, the team discovered a shared network guide containing password information. Though the passwords were outdated, they revealed a consistent pattern based on names, dates, and user initials.
This pattern allowed the team to create a custom password list, conduct a password spray, and eventually compromise an Active Directory (AD) administrator. The team then created a new administrator account and deleted the previous session, demonstrating how easily an attacker could cover his or her tracks.
Lastly, Red Sentry executed a DCSync attack to retrieve all user passwords, including the KRBTGT hash, which is critical for creating ‘golden tickets’ (allowing an attacker to impersonate any user with admin privileges)
This attack gave Red Sentry’s ethical hackers complete control over the school district’s network, showing how quickly a real-world cybercriminal could do the following:
Despite the district’s previous clean bill of health, Red Sentry uncovered critical school cybersecurity risks that could have led to a significant data breach. The entire process, from the initial assessment to the final report, was completed within two weeks.
Here are the highlights:
1. Full Network Compromise: Red Sentry gained administrative control over the school district’s entire IT infrastructure, including the most privileged accounts.
This would have allowed an attacker to do the following:
2. Systemic Password Vulnerabilities: Despite following Microsoft standard security guidelines, the district's password policies proved insufficient against modern attack techniques. The discovery of historical password patterns made it possible to predict current credentials.
3. Speed of Compromise: The entire process, from initial access to complete network compromise, took less than a day. It revealed just how vulnerable the system was to potential threats and how pentesting can help prevent a true data breach
Perhaps most surprising was the discovery that the initial point of compromise stemmed from a seemingly innocuous vulnerability in one of the district's printers.
Clearly, penetration testing for schools is extremely important and we must consider all potential attack vectors, no matter how insignificant they may seem.
Once Red Sentry’s pentest was completed, the company provided comprehensive recommendations, guidance, and implementable solutions.
While the district initially resisted changes because its practices met Microsoft's security guidelines, Red Sentry’s team demonstrated why these standards were insufficient for a complex, modern IT environment.
Red Sentry provided guidance on implementing a comprehensive security enhancement program. This included strengthening password policies, mitigating the KRBTGT vulnerability, securing privileged accounts, and addressing deeper vulnerabilities within the network infrastructure. According to the Cybersecurity & Infrastructure Security Agency, following best cybersecurity practices is essential for individuals and organizations.
Red Sentry worked closely with the district to break down the risks associated with the KRBTGT vulnerability and explained the exploit step-by-step.
It tailored its reporting to these two different business requirements:
Red Sentry’s approach to reporting ensured that both technical teams and leadership had the information they needed to properly secure their network.
The school district successfully implemented the recommended changes, with Red Sentry providing validation through follow-up testing.
This verification process confirmed that the dangerous vulnerabilities had been properly addressed and that the newly implemented safeguards were robust.
Red Sentry was able to support the school district by doing the following:
This case challenged the common yet dangerous assumption in education cybersecurity that following industry-standard guidelines is enough.
Despite the district's strict adherence to Microsoft's security recommendations, Red Sentry demonstrated how these baseline standards failed to protect against sophisticated modern attacks. This revelation transformed the district's approach to security, moving them beyond checkbox compliance.
With Red Sentry’s expertise and support, the district now has a faster, more thorough, and more transparent security testing process—one that truly keeps its students, staff, and data safe.
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