If you are required to allow inbound traffic to your VMs for business reasons, this next area is of critical importance. Use complexity for passwords and user account names There are limits to the number of rules and they can become difficult to manage if many users from various network locations need to access your VMs.įor more information, see this top Azure Security Best Practice:ģ. Network security groups contain rules that allow or deny traffic inbound to, or outbound traffic from several types of Azure resources including VMs. Just-in-time will allow you to reduce your attack service while also allowing legitimate users to access virtual machines when necessary.
You should always be cautious about allowing inbound network traffic from unlimited source IP address ranges unless it is necessary for the business needs of that machine.Ī couple of methods for managing inbound access to Azure VMs: This is just a partial list of commonly published ports. If you see many such events occurring in quick succession (seconds or minutes apart), then it means you are under brute force attack. Filter for Event ID 4625 (an account failed to log on).
#CODEMETER CONTROL CENTER ON AZURE VM WINDOWS#
If you are not using Security Center Standard tier open the Windows Event Viewer and find the Windows Security Event Log.Azure Defender (formerly Azure Security Center Standard) will alert you if your VM is under a brute force attack.It is relatively easy to determine if your VMs are under a brute force attack, and there are at least two methods we will discuss below: If that is the case, you should be concerned, and it’s quite possible that the VM could be under brute force attack right now. Find any rule that is publishing RDP and look to see if the Source IP Address is a wildcard (*). If you are already allowing RDP access to your Azure VMs from the internet, you should check the configuration of your Network Security Groups. Attackers are always scanning the entire range of ports, and it is trivial to figure out that you changed from 3389 to 4389, for example.
Do not be fooled into thinking that changing the default port for RDP serves any real purpose. Because of its popularity, it’s a very attractive target for threat actors. The Remote Desktop Protocol (RDP) is a remote access solution that is very popular with Windows administrators. Isolate management ports on virtual machines from the Internet and open them only when required Many of the recommendations below are included in Azure Secure Score. Otherwise, work on the highest priority items to improve the current security posture. If it is at 100 percent, you are following best practices. Secure Score within Azure Security Center is a numeric view of your security posture. Use Azure Secure Score in Azure Security Center as your guide
We will refer to the Azure Security Top 10 best practices as applicable for each: Best practices 1. The areas of the shared responsibility model we will touch on in this blog are as follows: This blog will share the most important security best practices to help protect your virtual machines. The diagram below illustrates the layers of security responsibilities:įortunately, with Azure, we have a set of best practices that are designed to help protect your workloads including virtual machines to keep them safe from constantly evolving threats.
Security is a shared responsibility between Microsoft and the customer and as soon as you put just one virtual machine on Azure or any cloud you need to ensure you apply the right security controls. This is one area in the cloud security shared responsibility model where customer tenants are responsible for security. One of the things that our Detection and Response Team (DART) and Customer Service and Support (CSS) security teams see frequently during investigation of customer incidents are attacks on virtual machines from the internet.