In a RDP (Remote Desktop Protocol) brute force attack, an attacker gains access to a victim’s computer by using brute force techniques which can effectively crack weak passwords.
Typically, the attacker scans a list of IP ranges for RDP port 3389 (default RDP port) which are open for connection. Once a port is found, the brute force attack is launched. The brute force technique uses a trial and error password guessing attack with a list of commonly used credentials, dictionary words, and other combinations.
Once the access is gained, the attacker can disable the system’s antivirus and run the malware payload. This means, even if the antivirus is updated and has a detection against the malware, turning off its protection renders the system defenseless.
Guardian Firewall feature can effectively prevent RDP brute force attacks by allowing only trusted IP addresses from accessing the system via remote desktop.
How to configure Firewall?
Guardian dashboard => Select Internet and Network => Firewall Protection=> Advanced Settings – Configure=> Traffic Rules.
A) To block all RDP connections:
B) To add exception for trusted systems:
Now save the changes made by clicking on OK and selecting Save Changes.
Note: Make sure that the RDP White-list rule is higher than the Allow Remote Desktop rule in the Firewall rule list.
Security practices to help avoid RDP brute forcing attacks
– Use strong and unique passwords on user accounts that cannot be easily breached. Weak passwords like Admin, admin@123, user, 123456, password, Pass@123, etc., can be easily brute forced in the first few attempts itself.
– Configure password protection for your security software. This would prevent any unauthorized users accessing the system from disabling or uninstalling it. Guardian users can enable this feature from the Settings => Password Protection.
– Disable the Administrator account and use a different account name for administrative activities. Most brute-force attempts are done on an Administrator user account as it is present by default. Also, remove any other unused or guest accounts if configured on the system.
– Change the default RDP port from the default‘3389’. Most attacks of such type focus on targeting the port 3389 of RDP.
– Enable Network Level Authentication (NLA) feature in your RDP settings available in Windows Vista and later OS.
Ref: https://technet.microsoft.com/en-us/library/cc732713.aspx
– Configuring Account Lockout Policies that automatically lock the account after a specific number of failed attempts. This feature is available in Windows and the threshold can be customized as per the administrator.
Ref: https://technet.microsoft.com/en-us/library/dd277400.aspx