SOCKS Proxy Primer: What Is SOCKs5 and Why Should You …
co-authored by Darshan S. Mulimath, Megha B. Sasidhar, and Ashiq Khader
In computer networks, a proxy or proxy server is a computer that sits between you and the server. It acts as a gateway between a local network and a large-scale network, such as the internet.
A proxy server works by intercepting connections between sender and receiver. All incoming data enters through one port and is forwarded to the rest of the network via another port.
Aside from traffic forwarding, proxy servers provide security by hiding the actual IP address of a server. They also have caching mechanisms that store requested resources to improve performance. A proxy server can encrypt your data so it is unreadable in transit and block access to certain webpages based on IP address.
Now that we have a general sense of how a proxy works, let’s zoom in on a specific type of proxy — SOCKS — and, specifically, the SOCKs5 variant.
What Is a SOCKS Proxy?
SOCKS, which stands for Socket Secure, is a network protocol that facilitates communication with servers through a firewall by routing network traffic to the actual server on behalf of a client. SOCKS is designed to route any type of traffic generated by any protocol or program.
A SOCKS proxy server creates a Transmission Control Protocol (TCP) connection to another server behind the firewall on the client’s behalf, then exchanges network packets between the client and the actual server. The SOCKS proxy server doesn’t interpret the network traffic between client and server in any way; it is often used because clients are behind a firewall and are not permitted to establish TCP connections to outside servers unless they do it through the SOCKS proxy server. Therefore, a SOCKS proxy relays a user’s TCP and User Datagram Protocol (UDP) session over firewall.
SOCKS is a layer 5 protocol, and it doesn’t care about anything below that layer in the Open Systems Interconnection (OSI) model — meaning you can’t use it to tunnel protocols operating below layer 5. This includes things such as ping, Address Resolution Protocol (ARP), etc. From a security perspective, it won’t allow an attacker to perform scans using tools such as Nmap if they are scanning based on half-open connections because it works at layer 5.
Since SOCKS sits at layer 5, between SSL (layer 7) and TCP/UDP (layer 4), it can handle several request types, including HTTP, HTTPS, POP3, SMTP and FTP. As a result, SOCKS can be used for email, web browsing, peer-to-peer sharing, file transfers and more.
Other proxies built for specific protocols at layer 7, such as an HTTP proxy that is used to interpret and forward HTTP or HTTPS traffic between client and server, are often referred to as application proxies.
There are only two versions: SOCKS4 and SOCKs5. The main differences between SOCKs5 and SOCKS4 are:
SOCKS4 doesn’t support authentication, while SOCKs5 supports a variety of authentication methods; and
SOCKS4 doesn’t support UDP proxies, while SOCKs5 does.
A SOCKs5 proxy is more secure because it establishes a full TCP connection with authentication and uses the Secure Shell (SSH) encrypted tunneling method to relay the traffic.
Why You Should Adopt SOCKs5
Below are four key benefits to using a SOCKs5 proxy with SSH tunneling.
1. Access Back-End Services Behind a Firewall
Usually, a cluster is hosted in the cloud behind a firewall to minimize potential security vulnerabilities. There are two ways to access any backend services that are running inside a cluster, and each has its limitations:
Expose backend services to public (and accept the associated security risk); or
Whitelist the client or user’s IP to allow traffic to backend services (this is not the right solution for when a user’s IP changes, however).
A SOCKs5 proxy with dynamic port forwarding using SSH can be an alternative to the two undesirable options above. An administrator or developer could access any backend services within a cluster that is hosted in the cloud behind a firewall for debugging, monitoring and administrating from a public network without exposing the backend service ports or whitelisting specific IPs.
Let’s look at a use case. For security reasons, the administration or monitoring application APIs or web user interface (UI) ports for monitoring Hadoop cluster are closed by default when hosted on the cloud. To access these APIs or web UIs, you can use SSH dynamic port forwarding to master or edge a node cluster, since the master node will have a public IP and run SSH services by default, which is exposed so the user can connect from outside.
For another example, say you’re working with a virtual private cloud (VPC). You can deploy a bastion host to securely access remote instances within a VPC by limiting their access to the outside world. You can access the bastion host from the outside world, and only port 22 (SSH) is opened. Using SSH dynamic port forwarding (SOCKs5 proxy), you can access the remote instances that are running in the VPC.
2. No Special Setup Required
SOCKs5 doesn’t require special setup, as long as you have SSH access to either the Edge node or gateway of a cluster. Therefore, users such as administrators and developers can access back-end resources behind the firewall using an SSH tunnel without requiring a virtual private network (VPN).
3. No Third-Party Public or Free Proxy Server in Your Deployments
Since a SOCKs5 proxy routes all kinds of TCP and UDP traffic to their respective service through SSH tunneling, no layer 7 application-related special proxies are required for each service to route application requests.
4. Fewer Errors, Better Performance
Unlike other application proxies, SOCKs5 does not rewrite data packets. It just relays the traffic between devices. Therefore, it is less prone to errors, and performance increases automatically.
How Does SOCKs5 Work in Practice?
Any CISO wouldn’t jump at the chance to embrace the benefits listed above. But what does a SOCKs5 proxy look like in the context of an enterprise security strategy? Where do security leaders begin when implementing SOCKs5 in their environment? Below are some key steps to help you get started.
Setting Up a SOCKs5 Proxy Connection
To SOCKSify an IT environment, the client application must have the capacity to support the SOCKs5 protocol. The syntax below is based on the SSH client on Linux; it shows how to create a SOCKs5 proxy server running on your local computer and then authenticate to the Edge node of a cluster or gateway hosted on cloud that routes traffic to the servers inside the cluster:
$ ssh -D 30001 [email protected] -C -f -N (password: xyz; or
$ ssh -i /path/to/private_key -D 30001 [email protected] -C -f -N
The above command starts the SOCKs5 server and binds to port 30001, then connects to Edge Node, Master Node or Gateway Node over the SSH tunnel hosted on the cloud.
The options used in the above command do the following:
D 30001 tells SSH to create a SOCKs5 server on port 30001 on the client computer.
C compresses data before sending.
N means “Do not execute a remote command. ” This is useful for simply forwarding ports (protocol version 2 only).
F requests SSH to go to the background just before command execution.
Accessing the Endpoints Using the SOCKs5 Protocol
Once a SOCKs5 proxy is created, configure your clients to access the internal services of the cluster. To keep it simple, we use a command line URL (cURL) that supports the SOCKs5 protocol. Other methods such as using a web browser require some additional setup and configurations.
The below cURL command shows how to access one of the HTTPS application endpoints listening on port 8000 behind a firewall using the SOCKs5 proxy over the SSH tunnel created above:
curl -x socks5hlocalhost:30001 -v -k -X GET EdgeNodeSSHserverIP:8000
The above cURL tool connects to port 30001 on localhost. Upon receiving a HTTP GET request on port 30001 from the cURL, the SSH client sends the same request via SSH tunnel to the SSH server.
The remote SSH server handles the request and passes the request to a back-end service listening at port 8000. The response is sent back to the client over the same SSH tunnel to the client’s SOCKs5 proxy. The proxy relays the response to the cURL, which displays the response.
Once you have created a SOCKs5 proxy using the SSH dynamic port forwarding method, you can also use the netcat utility to test the TCP connection. As shown below, a TCP connection test is made for back-end services listening at port 8443 with the SOCKs5 proxy:
ncat –proxy 127. 0. 1:30001 –proxy-type socks5 EdgeNodeSSHserverIP 8443 -nv
In Summary
A SOCKs5 proxy is a lightweight, general-purpose proxy that sits at layer 5 of the OSI model and uses a tunneling method. It supports various types of traffic generated by protocols, such as HTTP, SMTP and FTP. SOCKs5 is faster than a VPN and easy to use. Since the proxy uses a tunneling method, public cloud users can access resources behind the firewall using SOCKs5 over a secured tunnel such as SSH.
What are the benefits of SOCKS5 proxy? | NordVPN
ContentsWhat is SOCKS5 proxy? SOCKS5 proxy servers benefits1. Gets you around internet blocks2. Faster and more reliable connection3. Fewer errors and improved overall performance4. Better performance on P2P platformsSOCKS5 vs HTTP proxyShould you use SOCKS5 with a VPN? Should you use a free proxy? What is SOCKS5 proxy? SOCKS5 is the latest and most up-to-date SOCKS protocol. It is an improved version of SOCKS, an internet protocol that routes packets between a server and a client using a proxy server. SOCKS5 has enhanced security and offers three types of authentication methods: Null authentication – No authentication required to connect to a proxy;Username/password authentication – You need to provide login details to connect to a proxy;GSS-API authentication – Both you and the server use authentication methods at the operating system level to verify your does it work? Your traffic is routed through a proxy server that generates an arbitrary IP address before you reach your destination. Technically speaking, SOCKS5 (the latest version) uses proxy servers to form User Datagram Protocol (UDP) or Transmission Control Protocol (TCP) connections through arbitrary IP your IP is 1. 1. 1 and your traffic is routed through a SOCKS Proxy with the IP 2. 2. 2, the destination server (the website) will think that the request came from the latter. The website cannot see your original IP address. This helps you hide your location, but it doesn’t mean that your traffic is secure. Contrary to Virtual Private Networks (VPNs), proxies do not encrypt your traffic – it’s still out in the open and anyone can snoop on what you are is no such thing as an 100% anonymous SOCKS5 proxy server, because it’s impossible to be truly anonymous online. You can get close to it by being aware of what you do online, what services and security tools you use and how it all impacts your privacy. But no single proxy, VPN, or encrypted messaging app will make you ’s little chance you’ll be able to use streaming services that are not available in your country by connecting through a proxy. However, if you only want to change your virtual location and bypass simple geo-blocks, you can find a SOCKS5 proxy list online and try your luck. Check our brief video about SOCKS5 a SOCKS5 proxy better than a VPN? SOCKS5 is not as secure or as fast as a VPN. It’s easy to confuse a SOCKS5 proxy with a VPN, but there are curcial differences. Like most proxies, SOCKS5 won’t encrypt your data, and will lower internet speed and reover, SOCKS is quite detectable, so it most likely won’t get you around national firewalls. Due to this fact you need to enhance its security with a VPN. A good VPN, on the other hand, will encrypt your data as it travels from your device to the VPN server, ensuring that nobody can view it at any point on its journey. With a service like NordVPN, you can still get around internet restrictions and protect your IP address, but you’ll do so with genuine privacy and lightning fast internet speeds. Upgrade your privacy with high-quality VPN CKS5 proxy servers benefitsHere are 4 strong reasons to use SOCKS proxies:1. Gets you around internet blocksSince proxy servers act as relays between your device and the internet, they can easily help you bypass internet blocks. For example, if your IP was blacklisted by a certain website (or you use a VPN and its servers IPs were blacklisted) you can route your traffic through a SOCKS5 proxy and so bypass this block. However, it won’t help you to circumvent national firewalls in the way that a VPN will, as most of them use deep packet inspection (DPI). This means that your traffic is blocked by your ISP and before it reaches the website. Faster and more reliable connectionUnlike its predecessors, which only used TCP protocol, SOCKS5 proxy servers can use UDP protocol, ensuring a reliable connection and efficient TCP internet protocol forms a connection between a client and a server, making sure that all the packets arrive from one side to the other. It requires fitting the content into a fixed format so that it can be transferred easily. UDP, on the other hand, doesn’t focus on whether all packets from the client or server reach the other side and whether they are transferred in the same order. UDP doesn’t waste time converting data packets into a stream of fixed packets. Therefore, with these UDP at hand, SOCKS5 can offer faster speeds and a reliable connection. 3. Fewer errors and improved overall performanceMany other proxies rewrite data packet headers. Because of this, there’s a high chance of misrouting or mislabelling that data. SOCKS5 proxy servers do not rewrite data packet headers, so there is a lower chance for errors. Since there are far fewer errors, the performance automatically improves. However, this comes at a cost of your privacy and security as packet headers contain your personal information and can be easily identified. 4. Better performance on P2P platformsSOCKS5 is faster than other proxies because it transfers smaller data packets. Therefore, it offers faster download speeds, which is why many users use it to connect to P2P sharing websites and CKS5 vs HTTP proxyUnlike HTTP proxies, which can only interpret and work with HTTP and HTTPS webpages, SOCKS5 proxies can work with any proxies are high-level proxies usually designed for a specific protocol. While this means you get better connection speeds, they’re not nearly as flexible and secure as SOCKS proxies. SOCKS proxies are low-level proxies that can handle any program or protocol and any traffic without you use SOCKS5 with a VPN? The main difference between proxies and VPNs is that VPNs encrypt your traffic and proxies don’t. VPNs provide more stable connections while proxy connections drop more are few reasons to use both together, so your best bet is to choose the right tool for the job. Fortunately, NordVPN’s servers also support SOCKS5 connections. For full instructions on how to use SOCKS5 proxy on different platforms, visit our tutorial page. Should you use a free proxy? Because of their low overhead, proxy services aren’t expensive to run, but they still come with costs. Therefore, free proxies, like free VPNs, should be avoided. Here’s why:Poor performance. Free proxies will have less support personnel and may have less configuration options or slower infrastructure. All of this can make them slower and less secure. They might also reduce their speeds or turn off features in an effort to make you a paying ivacy issues. If you’re not paying for the service, you aren’t the customer. Free proxies can monitor user traffic and sell that data to third parties or serve ads. This means replacing ads on websites you love (thereby cutting into their revenue) or introducing new ads that weren’t there best bet is a premium proxy service, which will offer the best speeds, support, and security. Fortunately, when you buy NordVPN, you can also use some of our servers as SOCKS5 proxies. With all of our other features, you can easily switch between maximum security, maximum speed, or the best of both secure and flexible service offers tons of options, including SOCKS5. Try it with our risk-free money-back guarantee for 30 days!
Emily Green
Verified author
Emily Green is a content writer who loves to investigate the latest internet privacy and security news. She thrives on looking for solutions to problems and sharing her knowledge with NordVPN readers and customers.
Under Attack: How Threat Actors are Exploiting SOCKS Proxies
From the basic building blocks of the internet to cryptocurrency mining on a supercomputer, SOCKS sits at the core of computing. A SOCKS proxy can be used to improve network security in an enterprise, but can also be exploited by cybercriminals for nefarious reasons. Take a look at how SOCKS proxies have been manipulated recently by threat actors.
What is a SOCKS Proxy?
SOCKS, which stands for Socket Secure, is an internet protocol that enables the exchange of packets between a client and a server through a proxy server.
According to the Internet Engineering Task Force, the protocol is “designed to provide a framework for client-server applications in both the TCP (transmission control protocol) and UDP (user datagram protocol) domains to conveniently and securely use the services of a network firewall. ”
A proxy server functions as an intermediary for requests from a client in an internal network seeking services or resources from the internet. The proxy server has its own public IP address.
There are a number of use cases for a proxy server: to improve network security, carry out actions anonymously, balance network traffic, control employee internet usage and provide faster network speeds by compressing traffic, caching files and stripping ads from websites.
There are currently two versions of SOCKS: SOCKS4 and SOCKS5. SOCKS5 is the current version of the protocol. It supports a variety of authentication methods, as well as User Datagram Protocol (UDP) proxies.
There are several benefits to using the latest version of SOCKS for a proxy server. First, it enables an administrator to access backend services remotely within a cluster hosted in the cloud behind a firewall, without exposing the backend service ports. Second, it does not require anything special as long as there is secure shell (SSH) access to either the Edge node or gateway. Third, a SOCKS5 proxy can route test TCP (TTCP) and UDP traffic through SSH tunneling. Therefore, each service does not require a unique proxy to send requests. And finally, it does not rewrite data packets, so it makes fewer errors and improves performance.
SOCKS5 Proxies Used in Supercomputer Attacks
Unfortunately, a SOCKS proxy can be abused by attackers to carry out various types of nefarious activities.
A recent example involves cryptomining attacks on academic supercomputers used to conduct advanced research. The attackers were able to connect to a SOCKS5 proxy host running a microSOCKS instance on a high port. They did this by exploiting an SSH connection from the anonymous Tor network, according to research by the European Grid Infrastructure Foundation’s computer security incident response team. MicroSOCKS is a multithreaded, small SOCKS5 server.
Normally, researchers use the SSH connection to log in to the supercomputers remotely. The attackers were able to steal the SSH credentials and move between supercomputers using the stolen SSH credentials. The attackers then used the supercomputers to mine cryptocurrency.
The academic institutions running the supercomputers had to shut them down to clear the cryptomining malware, disrupting valuable academic research.
SOCKS5 Exploited by Dark Nexus Botnet
In another recent attack, the Dark Nexus internet of things (IoT) botnet was able to enlist a SOCKS proxy in a scheme offering distributed denial-of-service (DDoS) attacks for hire services.
The Dark Nexus attackers infect IoT devices and then run a SOCKS5 proxy on a randomly chosen port that connects with the command and control server as part of the registration, based on a Bitdefender analysis.
Bitdefender researchers believe the attackers are selling access to the SOCKS5 proxies on an underground forum. However, they do not have direct evidence to support this belief.
In addition, the Gwmndy botnet abused SOCKS proxy servers. Gwmndy attackers targeted Fiberhome routers and added 200 routers per day to their botnet, stopping after reaching that number, according to 360 Netlab researchers.
Instead of using the botnet for DDoS attacks, cryptojacking, sending spam or stealing data, the Gwmndy botnet operators appeared to use the routers for SSH tunneling proxy nodes and creating a SOCKS5 proxy service locally.
Ransomware Attackers Abuse SOCKS Proxies
Ransomware attackers also use SOCKS proxies. The QNAPCrypt ransomware, which focused on infecting network-attached storage Linux devices, exploited authentication methods used by companies to establish connections through a SOCKS5 proxy, according to Intezer researchers.
Central to the multistage QNAPCrypt ransomware attack is a SOCKS5 proxy. First, the ransomware connects to a SOCKS5 proxy. The proxy requests the victim’s configuration keys to retrieve the ransomware client from an Onion domain. It retrieves an RSA public key, unique Bitcoin wallet and ransom note from the Onion domain. After going through the SOCKS5 proxy again, the ransomware proceeds to encrypt the victim’s systems using the retrieved keys.
While most ransomware attacks target Windows systems, QNAPCrypt joins a growing list of ransomware going after Linux-based systems.
Cloud Snooper and SOCKS Proxies
Cloud Snooper malware uses a SOCKS proxy to bypass firewalls in cloud infrastructure. The malware, a backdoor trojan, can be executed as a command-line tool and as a daemon.
Cloud Snooper opens HTTP or domain name system (DNS) services on an infected system and enables traffic tunneling, operating both as a reverse SOCKS5 proxy server and client, explains SophosLabs researchers. The SOCKS5 proxy server used by the malware is based on the open-source sSOCKS proxy implementation.
In addition, the fileless Nodersok malware exploited a SOCKS proxy to compromise thousands of PCs last year. The malware first installs an HTML application (HTA) on the targeted computer, which runs the HTA files and exploits Excel, JavaScript and PowerShell scripts.
The malware then abuses and WinDivert to start a SOCKS4 proxy on infected computers. This turns them into proxies for sending malicious traffic. Next, the malware connects to the attackers’ command and control server. The server uses the SOCKS4 protocol to send an HTTP request to the client. The client proxies the request to the website and returns the response and the HTML page to the server.
Using SOCKS proxy and other stealth components enables the malware to “fly under the radar” for a while. Therefore, it is best to use strong authentication to lessen the risk that SOCKS proxies are hijacked by attackers.
Frequently Asked Questions about sox proxy
Is SOCKS and proxy the same?
Unlike HTTP proxies, which can only interpret and work with HTTP and HTTPS webpages, SOCKS5 proxies can work with any traffic. HTTP proxies are high-level proxies usually designed for a specific protocol. … SOCKS proxies are low-level proxies that can handle any program or protocol and any traffic without limitations.
What is SOCKS proxy malware?
The SOCKS5 proxy server used by the malware is based on the open-source sSOCKS proxy implementation. … This turns them into proxies for sending malicious traffic. Next, the malware connects to the attackers’ command and control server. The server uses the SOCKS4 protocol to send an HTTP request to the client.Sep 3, 2020
How do you use a SOCKS proxy?
Using SOCKS5 Proxy for US Netflix Go to Advanced and click the Network tab. Under Connection > Configure how Firefox connects to the Internet, click Settings… First, change Configure Proxies to Access the Internet to Manual proxy configuration. Under SOCKS Host enter the URL or IP address of your proxy server.