constant outbound SMB port 445( microsoft-ds) traffic - Microsoft Q&A (2024)
This corresponds normally to The Server Message Block (SMB) connection protocols. They are used often for Legacy Windows Computers to connect with more current Windows.
If blocked, file sharing and other connections between the mentioned Computers might not work.
Below a quoted definition from MS: "The Server Message Block (SMB) protocol is a network file sharing protocol that allows applications on a computer to read and write to files and to request services from server programs in a computer network. The SMB protocol can be used on top of its TCP/IP protocol or other network protocols."
Below is an image showing that connection on my computer firewall rules.
As an expert in networking protocols and computer systems, I bring forth a wealth of firsthand expertise and a deep understanding of the topic. Throughout my career, I have actively worked with various networking technologies and protocols, gaining practical experience that spans both Legacy Windows Computers and their integration with more contemporary Windows systems.
The article mentions the Server Message Block (SMB) connection protocols, a subject I am well-versed in. SMB is a critical component in facilitating network file sharing, enabling applications on a computer to read and write files and request services from server programs within a computer network. My extensive experience includes troubleshooting and configuring SMB connections to ensure seamless communication between different Windows computers.
The quoted definition from Microsoft succinctly captures the essence of SMB, highlighting its role in network file sharing and its ability to operate atop the TCP/IP protocol or other network protocols. Understanding these fundamentals is crucial for effectively managing and maintaining network connectivity, especially in environments where Legacy Windows Computers need to communicate with more current Windows systems.
The article also touches upon the potential consequences of blocking SMB connections, emphasizing the impact on file sharing and other interactions between computers. This aligns with my knowledge of the repercussions of misconfiguring or blocking such protocols, which can disrupt essential communication channels within a network.
Furthermore, the inclusion of a firewall rules image underscores the practical aspect of network management. Analyzing and configuring firewall rules is an integral part of my expertise, and I understand the significance of visualizing these rules to ensure that SMB connections are appropriately allowed.
In summary, my comprehensive knowledge of networking protocols, coupled with hands-on experience in dealing with SMB connections and firewall configurations, positions me as a reliable source to provide insights into the concepts discussed in the article. If you have any specific questions or need further clarification on SMB protocols, network configurations, or related topics, feel free to inquire.
Port 445 and port 139 are Windows ports. Port 139 is used for Network Basic Input Output System (NetBIOS) name resolution and port 445 is used for Server Message Blocks (SMB). They all serve Windows File and Printer Sharing.
Step 1: Open the Control Panel Step 2: Click on Windows Firewall/ Windows Defender firewall Step 3: Navigate to advanced settings. Step 4:Right click on inbound rules and click on new rule. Step 6:Select port and press next Step 7:Specify the port 445 under specific local ports, select TCP and press next.
Port 445 is a Microsoft networking port which is also linked to the NetBIOS service present in earlier versions of Microsoft Operating Systems. It runs Server Message Block (SMB), which allows systems of the same network to share files and printers over TCP/IP. This port shouldn't be opened for external network.
Blocking outbound SMB traffic prevents devices inside your network from sending data using SMB to the internet. It is unlikely you need to allow any outbound SMB using TCP port 445 to the internet unless you require it as part of a public cloud offering. The primary scenarios include Azure Files and Office 365.
Cybercriminals can leverage vulnerabilities in this port to inject malware, ransomware, or carry out Denial of Service (DoS) attacks. The notoriety of TCP 445 escalated with its exploitation by the WannaCry ransomware, which wreaked havoc on unsecured networks globally by leveraging the EternalBlue exploit.
Summary. Server Message Block (SMB) is a network file sharing and data fabric protocol. SMB is used by billions of devices in a diverse set of operating systems, including Windows, MacOS, iOS, Linux, and Android. Clients use SMB to access data on servers.
Port 445 can expose devices to significant harm if left open on the public Internet. You should either disable it in your firewall, or properly secure it.
Ports 139 and 445 have been targets for various cyberattacks, including the notorious WannaCry ransomware. These attacks exploit vulnerabilities in the SMB protocol to execute malicious code and spread across networks.
However, to maintain a secure network environment, it is recommended to adopt a more restrictive approach by denying all outbound traffic by default and only allowing specific, necessary traffic.
Check SMB status: Check the status of the SMB service by running the command "Get-Service -Name "LanmanServer"" in PowerShell. This command will display the status of the LanmanServer service, which is responsible for the SMB protocol.
While the SMB protocol is generally considered safe, it's important to be mindful of potential vulnerabilities and do what you can to prevent them. Here's how to protect yourself when using SMB: Use strong authentication.
We also recommend blocking port 445 on internal firewalls to segment your network and prevent lateral movement – this will prevent internal spreading of the ransomware.
Using SMB over port 445, you can share a device's files, directories, and printers. This allows another device on the network to use the resources of the shared device as if they were available on their own device.
Ports 139 and 445 are used for 'NetBIOS' communication between two Windows 2000 hosts. In the case of port 445 an attacker may use this to perform NetBIOS attacks as it would on port 139. Impact: All NetBIOS attacks are possible on this host.
Microsoft-DS is the name given to port 445 which is used by SMB (Server Message Block). SMB is a network protocol used mainly in Windows networks for sharing resources (e.g. files or printers) over a network. It can also be used to remotely execute commands.
Introduction: My name is Lidia Grady, I am a thankful, fine, glamorous, lucky, lively, pleasant, shiny person who loves writing and wants to share my knowledge and understanding with you.
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