Source: NetDiligence - URS Partner
Protecting Your Organization from Credential-Based Ransomware Attacks: Strategies for 2025
Ransomware attacks surged in 2024, with 58% of incidents stemming from compromised login credentials, particularly through vulnerabilities in perimeter security appliances like firewalls, according to Coalition’s Cyber Threat Index 2025. To understand this growing threat and how small and medium-sized enterprises (SMEs) can safeguard against it, we spoke with Matt Dowling, a cybersecurity expert from Surefire Cyber. Below, we explore the latest trends in ransomware tactics, common vulnerabilities, and actionable steps to strengthen your defenses.
The Rising Threat of Credential-Based Ransomware
How are attackers gaining access, and what’s changed in their tactics?
Ransomware actors continue to exploit familiar entry points, with Virtual Private Networks (VPNs) and firewall vulnerabilities leading the charge. While phishing and Remote Desktop Protocol (RDP) attacks have slightly declined, unsecured VPNs without multi-factor authentication (MFA) and unpatched firewall vulnerabilities remain prime targets. Attackers are capitalizing on these weaknesses, particularly in organizations with outdated security practices, to gain initial access.
How Attackers Obtain and Exploit Credentials
What methods are cybercriminals using to steal credentials?
Attackers often seize opportunities through:
Brute Force Attacks: Targeting weak or reused passwords.
Zero-Day Exploits: Leveraging unpatched vulnerabilities in firewalls or VPNs.
Data Leaks: Acquiring credentials from previous breaches or dark web marketplaces.
Phishing: Less common but still a factor, particularly in business email compromise (BEC) scenarios.
SMEs, especially those with limited cybersecurity budgets, are prime targets due to weaker controls compared to larger enterprises with robust patch management and MFA.
Industries Most at Risk
Which sectors face the greatest threat from credential-based ransomware?
Certain industries are particularly vulnerable due to their sensitive data and limited cybersecurity resources:
Healthcare: Targeted for valuable Protected Health Information (PHI), often used in double-extortion schemes.
Education: Lacks stringent controls, making it an easy target.
Municipalities and Manufacturing: Budget constraints and lower cybersecurity maturity increase exposure.
These sectors must prioritize security investments to close gaps and deter attackers.
Critical Security Gaps in VPNs and Firewalls
What are the most common weaknesses in VPN and firewall configurations?
The most exploited vulnerabilities include:
Lack of Multi-Factor Authentication (MFA): Single-factor authentication leaves VPNs exposed.
Inadequate Patch Management: Failure to update firewalls, especially SonicWall and Fortinet SSL VPNs, creates entry points for attackers.
Without MFA and timely patches, organizations are sitting ducks for ransomware actors. Regular monitoring and updates are non-negotiable to prevent breaches.
How Attackers Move Within Networks
What happens after attackers gain access through stolen credentials?
Once inside via a compromised VPN, attackers operate as if physically connected to the network. Their steps include:
Reconnaissance: Scanning the network to identify critical systems.
Privilege Escalation: Gaining higher-level permissions to access sensitive servers.
Lateral Movement: Targeting backup servers, file servers, or other high-value assets for data exfiltration or encryption.
Ransomware actors move swiftly, often with a dwell time of just a few days, making early detection critical.
The Role of Access Brokers
Are stolen credentials being traded on the dark web?
Yes, access brokers are increasingly selling compromised VPN, firewall, and RDP credentials on dark web marketplaces. After initial compromise and reconnaissance, credentials are often sold to other threat actors who execute the ransomware attack. This delay between initial access and encryption highlights the importance of continuous monitoring to detect suspicious activity early.
Top Strategies to Prevent Credential-Based Ransomware
How can organizations protect themselves from these attacks?
To mitigate ransomware risks, organizations should:
Implement Multi-Factor Authentication (MFA): Secure all remote access points, especially VPNs, with MFA.
Adopt the Principle of Least Privilege: Grant VPN access only to essential personnel and disable it when not needed.
Prioritize Patch Management: Regularly update firewalls and software to close vulnerabilities.
Monitor Logs Actively: Use Managed Detection and Response (MDR) solutions to analyze firewall logs for anomalous activity, such as failed logins or unusual locations.
Deploy Endpoint Detection and Response (EDR): Detect and block threats within the network before ransomware is deployed.
Emerging Technologies for Enhanced Security
What tools can help detect and block unauthorized access?
Advanced security solutions are critical for staying ahead of threats:
Managed Detection and Response (MDR): Integrates with firewalls to monitor logs and detect anomalies like suspicious logins or unusual authentication patterns.
Endpoint Detection and Response (EDR): Identifies threats as they move within the network, often stopping attackers before encryption occurs.
Organizations that actively monitor firewall and network activity are more likely to catch threat actors early, preventing costly breaches.
Immediate Actions for Suspected Credential Compromise
What should organizations do if they suspect a breach?
If credentials are compromised:
Disable the SSL VPN: Immediately block the compromised access point on the firewall.
Activate Your Incident Response Plan: Notify your insurance carrier and engage a cybersecurity firm for an investigation.
Investigate Lateral Movement: Check for signs of persistence or data exfiltration beyond the initial access point.
Consider Disabling Internet Access: If containment is uncertain, weigh the option of temporarily shutting down external connectivity.
Swift action can limit damage and prevent escalation.
The Future of Ransomware Threats
Will credential-based ransomware attacks persist?
As remote work remains prevalent, VPN and firewall vulnerabilities will continue to be exploited. While organizations may improve MFA adoption and patch management, cybercriminals are likely to evolve, developing MFA bypass techniques and new exploit methods. Staying proactive with monitoring, updates, and employee training is essential to keep pace with these threats.
Final Thoughts:
Strengthening Your Cybersecurity Posture
Credential-based ransomware attacks are a persistent threat, but organizations can significantly reduce their risk by implementing MFA, prioritizing patch management, and leveraging advanced monitoring tools like MDR and EDR. By staying vigilant and adopting a proactive cybersecurity strategy, SMEs can protect their networks and avoid becoming the next ransomware statistic.
For more information on enhancing your cybersecurity, explore resources at HHS.gov for healthcare-specific guidance
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