How to Secure Your Business’s Remote Desktop Protocol (RDP) Connections

Remote Desktop Protocol (RDP) is a widely used tool that allows employees to remotely access business systems, making it invaluable for organizations with remote or distributed workforces. While RDP is an essential tool for remote access, it also poses significant cybersecurity risks if not properly secured. Cybercriminals frequently target RDP connections to gain unauthorized access to business systems, steal data, or deploy ransomware.

In this blog, we’ll explore the risks associated with RDP and outline the best practices your business can implement to secure RDP connections, ensuring remote access without compromising security.

1. Why RDP Security Is Crucial

RDP enables remote control of another computer over a network connection, providing access to desktop environments, files, and applications. However, if improperly secured, RDP can expose businesses to several cybersecurity threats:

– Brute-Force Attacks: Cybercriminals often use automated tools to perform brute-force attacks on RDP connections, attempting thousands of username-password combinations to gain access.
– Exploiting Unpatched Vulnerabilities: Attackers exploit vulnerabilities in RDP software to breach systems. If not regularly updated, these vulnerabilities can provide a backdoor into your business network.
– Ransomware Deployment: Once attackers gain access via RDP, they can deploy ransomware, encrypting business data and demanding payment for decryption.
– Lateral Movement: After breaching one system through RDP, attackers can move laterally across the network, compromising additional systems and sensitive data.

Securing your RDP connections is essential to prevent unauthorized access, data breaches, and ransomware attacks.

2. Key Security Risks Associated with RDP

Before diving into how to secure RDP connections, it’s important to understand the key risks businesses face when using this tool:

a. Weak or Reused Passwords

Weak or reused passwords are a primary vulnerability when securing RDP connections. Attackers use brute-force techniques or credential-stuffing attacks (using passwords stolen from other breaches) to gain access to RDP sessions. Passwords that are simple or used across multiple accounts make it easier for attackers to compromise your systems.

b. Unrestricted RDP Access

Exposing RDP to the open internet without any restrictions allows attackers to easily find and target your systems. Cybercriminals can scan the internet for open RDP ports (typically port 3389) and attempt to break in.

c. Unpatched Software

RDP vulnerabilities, such as the well-known “BlueKeep” vulnerability, can be exploited by attackers if they are not patched. Older or unpatched versions of RDP make it easier for cybercriminals to gain unauthorized access.

d. Lack of Multi-Factor Authentication (MFA)

Without multi-factor authentication (MFA), attackers only need a username and password to access your RDP connection. If credentials are compromised, there are no additional security layers to prevent unauthorized access.

3. Best Practices to Secure Your RDP Connections

To protect your business from RDP-related attacks, you must take a multi-layered approach to securing remote desktop connections. Below are the best practices for ensuring that your RDP access remains secure:

a. Use Strong Passwords and Account Lockout Policies

Why Strong Passwords Matter:
Weak or simple passwords make it easy for attackers to brute-force their way into your RDP sessions. To reduce the risk, enforce strong password policies that require complex passwords with a combination of upper- and lowercase letters, numbers, and symbols.

How to Strengthen Password Security:
– Enforce password complexity requirements.
– Implement a minimum password length (at least 12 characters).
– Prohibit password reuse across multiple systems.
– Require regular password changes.

Account Lockout Policies:
Set up account lockout policies that temporarily lock accounts after several failed login attempts. This helps prevent automated brute-force attacks, as attackers will be locked out after a certain number of unsuccessful attempts.

b. Enable Multi-Factor Authentication (MFA)

Why MFA is Essential:
MFA adds an additional layer of security by requiring users to provide two or more forms of identification before accessing RDP. Even if an attacker obtains a password, they won’t be able to access the system without the second authentication factor, such as a one-time code or biometric verification.

How to Implement MFA for RDP:
– Use an MFA solution that integrates with RDP, such as Microsoft Authenticator, Duo Security, or Google Authenticator.
– Require MFA for all users accessing RDP, especially for administrative accounts.

c. Limit RDP Access to Specific IP Addresses

Why Limiting Access is Important:
Exposing RDP to the entire internet significantly increases your attack surface. Instead, restrict access to RDP by limiting it to specific IP addresses or networks that are authorized to connect.

How to Restrict RDP Access:
– Use firewalls or VPNs to limit which IP addresses can access RDP.
– Set up network-level authentication (NLA) to add an additional layer of security before users can access the login screen.
– Only allow RDP access from trusted networks, such as your business’s internal network or known remote employees.

d. Change the Default RDP Port

Why Changing the Default Port Helps:
By default, RDP uses port 3389. Attackers often scan this port to identify open RDP connections. Changing the default port can reduce the likelihood of your system being targeted in such scans.

How to Change the RDP Port:
– Change the default RDP port to a non-standard port number (e.g., 3390 or higher).
– Keep track of the new port number and ensure that your firewall rules allow traffic on the new port.

Although this is not a foolproof solution, it makes it harder for attackers to find your RDP connection.

e. Use a Virtual Private Network (VPN)

Why VPN is Critical for RDP Security:
A VPN encrypts the connection between remote users and the business network, ensuring that all data exchanged during the RDP session is secure. Additionally, VPNs can hide the RDP server from the public internet, reducing the risk of unauthorized access.

How to Secure RDP with a VPN:
– Require employees to connect to a corporate VPN before accessing RDP.
– Use strong encryption protocols for the VPN (such as OpenVPN or IPSec) to ensure secure communication.
– Configure the VPN to require MFA for an additional layer of security.

f. Apply Regular Patches and Updates

Why Patching is Essential:
Cybercriminals often exploit vulnerabilities in outdated RDP software. Regularly patching and updating your systems ensures that known vulnerabilities are closed, reducing the risk of exploitation.

How to Keep RDP Updated:
– Regularly check for security patches and updates from your operating system vendor (such as Microsoft for Windows RDP).
– Apply patches as soon as they become available, especially for critical vulnerabilities like “BlueKeep.”
– Enable automatic updates where possible to ensure that your systems stay up-to-date.

g. Implement Network-Level Authentication (NLA)

What NLA Does:
Network-Level Authentication (NLA) is a security feature that requires users to authenticate before establishing an RDP session. This prevents unauthorized users from accessing the RDP login screen without first providing valid credentials.

How to Enable NLA:
– Enable NLA on your RDP server to ensure that only authenticated users can establish RDP sessions.
– Ensure that your users are running supported versions of Windows that can handle NLA.

h. Audit and Monitor RDP Access

Why Monitoring RDP Sessions is Important:
Monitoring and logging RDP access provides visibility into who is using RDP, from where, and when. This allows your IT or security teams to detect suspicious behavior, such as failed login attempts or unusual access patterns.

How to Monitor RDP Access:
– Enable logging of RDP sessions to track user activity.
– Set up real-time alerts for suspicious login attempts, such as repeated failed logins or logins from unknown IP addresses.
– Use Security Information and Event Management (SIEM) tools to aggregate and analyze logs for potential threats.

i. Disable RDP When Not in Use

Why Disabling RDP Can Enhance Security:
If your organization does not require continuous use of RDP, consider disabling it when it is not needed. Leaving RDP enabled unnecessarily increases the risk of exposure.

How to Disable RDP:
– Disable RDP on systems where remote access is not required.
– For temporary remote access needs, enable RDP only when necessary and disable it immediately after use.

This practice reduces the attack surface by ensuring that RDP is only available when needed.

4. What to Do If You Suspect an RDP Attack

If you suspect that your business’s RDP connections have been compromised, act quickly to mitigate the damage and prevent further breaches:

– Immediately disable RDP access to prevent unauthorized users from continuing to access the system.
– Reset passwords for all affected accounts and ensure that MFA is enabled for all users.
– Review logs to identify how the breach occurred and which systems were accessed.
– Notify your IT and security teams to investigate the breach and take remedial action, such as isolating compromised systems, removing malware, or restoring from backups.

Conclusion

Remote Desktop Protocol (RDP) is an essential tool for many businesses, but it must be properly secured to prevent cyberattacks. By implementing best practices like strong passwords, multi-factor authentication, VPNs, and regular patching, businesses can significantly reduce the risk of RDP-based attacks. Securing RDP connections should be part of a broader cybersecurity strategy that includes continuous monitoring, user education, and proactive threat detection.

Ensuring the safety of RDP access not only protects sensitive data but also ensures business continuity in a remote work environment.