BPL Logo Banner
CareersContact

In previous installments of The Attacker’s Playbook, we explored how human error (Part 1) creates the initial opportunity and how attackers exploit forgotten physical and digital entry points (Part 2).

But truth be told, we don’t always have to work that hard. Often, the “keys to the kingdom” are left right out in the open, in the form of default passwords, reused credentials, and sensitive data stored in the wrong places.

Ghost Keys in the Machine: The Danger of Default & Weak Passwords

The simplest access control failures are often the most effective. We operate under the principle that default credentials are the same as having no authentication at all.

The Flaw: We find these “ghost keys” everywhere, from routers and medical software to printers. One of the most glaring examples involved finding cameras in medical rooms with live feeds of patients, accessible to anyone who knew the default password.

However, the risk extends beyond defaults. Attackers also hunt for the obscure Active Directory (AD) attribute known as PassNotReq” (Password Not Required). If this is set to true, the user can circumvent password policies and set any password they want—including a blank one.

We use specialized tools like AD-RECON, an Active Directory reconnaissance tool developed by BreakPoint Labs, to quickly triage Bloodhound data and identify accounts with this attribute, as they are likely configured with weak or nonexistent passwords.

The Attack: An attacker will always start by checking for default credentials and password reuse. They look for exposed configuration files or scripts, such as a PowerShell script that sets the same local admin password across the network, which is essentially a reusable key to the entire kingdom.

In one engagement, we found a Domain Admin account from 2003 with a completely blank password. It’s important to note that this blank password wasn’t a default setting; It was a human-configured error that had remained undetected since its inception in 2003. Why did it persist for so long? Because vulnerability scanners generally don’t check AD password complexity or perform brute-force attacks, and pentesters often assume “blank” won’t work, so they don’t even try it.

The Result: A single default password can allow an attacker to gain a critical foothold, view sensitive patient video, or even achieve full domain takeover.

Mitigation Strategies: Basic security hygiene is non-negotiable.

The Data Graveyard: When Sensitive Information Goes Walkabout

So, why discuss passwords and data in the same post? Because they are the two halves of the “Keys to the Kingdom.” Passwords are the key, and the data is the treasure inside the chest. Once an attacker uses those weak credentials to get in, they immediately start hunting for the data you forgot about.

The Flaw: It’s extremely common to find Protected Health Information (PHI) and PII on systems where it has no business being. This data sprawl is typically the result of human error and a lack of training or convenience, like a doctor bypassing the secure network to use the Guest WiFi for faster internet access. We often find ourselves asking, “Why is there an exposed network share containing not just PHI, but old ransomware artifacts?”

The Attack: An attacker with internal access will hunt through these misplaced files. In one instance, we discovered dumps of email communications between thousands of students and their school’s healthcare center, filled with vast amounts of PHI and left on an easily accessible share.

The Result: This lack of data governance creates a massive, hidden risk. A single compromised workstation can lead to a catastrophic data breach if that station has access to years of forgotten, sensitive files.

Mitigation Strategies: Data governance is a critical, often-overlooked security control.

Protecting Your Critical Data

Leaving keys and sensitive documents out in the open is an invitation to attackers. Whether it’s a text file, an unlocked port, or a default password, poor security hygiene is an attacker’s best friend.

Key Takeaways:

Beyond compliance, protecting patient data is about resilience. Our security assessments simulate how attackers exploit these weaknesses, helping you find and fix them before they’re used against you.


So what happens once we’ve got the keys? That’s when the real damage begins. In the final chapter, we dive deep into the maze of internal trust—exploiting complex Active Directory paths that scanners can’t see. Part 4 is where persistence and privilege collide.


Cyber threats are growing more sophisticated, and attackers are increasingly exploiting
weaknesses that traditional vulnerability scanners simply aren’t designed to catch. In our recent
webinar, “Beyond Vulnerability Scanners: 10 Ways Attackers Exploit Healthcare Networks,” we
explored these blind spots and how adversaries take advantage of them. Watch the full webinar
here.

This blog post breaks down the top ten vulnerabilities discussed during the session, along with
actionable strategies your organization can use to close security gaps and harden your network
defenses.

  1. Weak Passwords and Password Reuse
    Weak and reused passwords, especially in service accounts or legacy systems lacking two-
    factor authentication (2FA), are prime targets. According to Verizon’s DBIR, over 80% of
    breaches involve compromised credentials. Passwords like keyboard walks (Qwerty123!) are
    easily guessable yet frequently used.

    To reduce this risk:
    • Regularly audit passwords and utilize password cracking exercises.Implement Group Managed Service Accounts to automate password rotation.

  2. Active Directory Certificate Abuse
    Misconfigured Active Directory certificate templates allow attackers to request certificates
    impersonating highly privileged users. Tools like Certify and CertiPy quickly identify vulnerable
    templates.

    Immediate action:
    • Regularly audit certificate template permissions.Restrict permissions strictly to essential accounts only.

  3. Kerberoasting
    Attackers exploit weak passwords associated with Service Principal Names (SPNs) to retrieve
    hashes for offline password cracking, directly threatening Active Directory security.

    Recommendations:
    • Regularly review accounts with SPNs to minimize exposure.
    • Use strong passwords or Microsoft’s Group Managed Service Accounts.

  4. Sensitive Data on Network Shares
    Sensitive data like PHI or system credentials often resides unnoticed on network shares.
    A free tool, Snaffler, can help quickly identify this exposure.

    Actions:
    • Regularly audit network shares.Remove or encrypt sensitive data promptly.

  5. Internal Web Application Vulnerabilities
    Healthcare networks often host numerous internal web applications, many of which are
    unnoticed and insecure. Use tools like GoWitness to visualize web applications, and consider
    specialized assessments using tools like Burp Suite Professional.

    Steps:
    • Regularly identify and disable unnecessary web services.Conduct frequent, targeted web application assessments.

  6. Active Directory Permission Misconfigurations
    Misconfigured permissions in Active Directory, such as excessive access via the ‘Everyone’
    group or improperly disabled accounts, pose significant risks. Tools like BloodHound and our
    custom-developed tool, AD Recon, provide detailed visibility into complex permission
    structures.

    Recommendations:
    • Conduct detailed Active Directory audits using tools like BloodHound and AD Recon.Regularly review disabled accounts and their permissions

  7. Relay Attacks (SMB and LLMNR Poisoning)
    Common misconfigurations, like disabled SMB signing, allow attackers to intercept and relay
    authentication requests. Use Responder in analyze mode to safely identify vulnerable
    configurations.

    Mitigation:
    • Enforce SMB signing across your environment.Disable unnecessary protocols like LLMNR.

  8. Default Credentials and Configurations
    Default credentials remain a pervasive issue, often found in IoT devices, printers, and legacy
    systems. Tools like Default HTTP Login Hunter help identify default credentials.

    Essential actions:
    • Regularly audit and change default credentials.Ensure rigorous device and system configuration management.

  9. Lack of Effective Detection Capabilities
    Many organizations rely heavily on endpoint protection, leaving internal network monitoring overlooked. Common attacker techniques like DC Sync or Kerberoasting often go unnoticed.

    Recommendations:
    • Implement comprehensive network monitoring solutions.
    • Develop specific alerts for common attack techniques.

  10. Weak Password Reset Procedures
    Social engineering remains highly effective, especially through weak help desk password reset
    processes. Attackers frequently exploit overly trusting help desk procedures.

    Immediate steps:
    • Implement and regularly test robust verification processes for password resets.Conduct frequent awareness and procedural training for help desk staff.

Key Takeaways

By understanding and addressing these ten common overlooked risks, organizations can
significantly strengthen their security posture beyond traditional vulnerability scanning. These
actionable insights offer a proactive path to defending your network and safeguarding sensitive
data from sophisticated attackers.

Stay tuned for follow-up content where we will dive deeper into the practical use of the tools
mentioned in the webinar.

chevron-down