computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...

, the term remote desktop refers to a

software Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists ...

- or

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

feature that allows a

personal computer A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...

desktop environment In computing, a desktop environment (DE) is an implementation of the desktop metaphor made of a bundle of programs running on top of a computer operating system that share a common graphical user interface (GUI), sometimes described as a graphica ...

to be run remotely off of one system (usually a PC, but the concept applies equally to a

server Server may refer to: Computing *Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients Role * Waiting staff, those who work at a restaurant or a bar attending customers and su ...

or a

smartphone A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whic ...

), while being displayed on a separate client device. Remote desktop applications have varying features. Some allow attaching to an existing user's session and "remote controlling", either displaying the remote control session or blanking the screen. Taking over a desktop remotely is a form of remote administration.

Overview

Remote access can also be explained as the remote control of a computer by using another device connected via the internet or another network. This is widely used by many computer manufacturers and large businesses help desks for technical troubleshooting of their customer's problems. Remote desktop software captures the mouse and keyboard inputs from the local computer (client) and sends them to the remote computer (server). The remote computer in turn sends the display commands to the local computer. When applications with many graphics including video or 3D models need to be controlled remotely, a remote workstation software that sends the pixels rather than the display commands must be used to provide a smooth, like-local experience. Remote desktop sharing is accomplished through a common client/server model. The client, or VNC viewer, is installed on a local computer and then connects via a network to a server component, which is installed on the remote computer. In a typical VNC session, all keystrokes and mouse clicks are registered as if the client were actually performing tasks on the end-user machine. Remote desktops also have a major advantage for security development, companies are able to permit software engineers who may be dispersed geographically to operate and develop from a computer which can be held within the companies office or cloud environment. The target computer in a remote desktop scenario is still able to access all of its core functions. Many of these core functions, including the main clipboard, can be shared between the target computer and remote desktop client.

Uses

A main use of remote desktop software is remote administration and remote implementation. This need arises when software buyers are far away from their software vendor. Most remote access software can be used for " headless computers": instead of each computer having its own monitor, keyboard, and mouse, or using a KVM switch, one computer can have a monitor, keyboard, mouse, and remote control software, and control many headless computers. The duplicate desktop mode is useful for user support and education. Remote control software combined with telephone communication can be nearly as helpful for novice computer-users as if the support staff were actually there. Remote desktop software can be used to access a remote computer: a physical personal

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

to which a user does not have physical access, but that can be accessed or interacted with. Unlike servers, remote computers are mainly used for peer to peer connections, where one device is unattended. A remote computer connection is generally only possible if both devices have a network connection. Since the advent of cloud computing remote desktop software can be housed on USB hardware devices, allowing users to connect the device to any PC connected to their network or the Internet and recreate their desktop via a connection to the cloud. This model avoids one problem with remote desktop software, which requires the local computer to be switched on at the time when the user wishes to access it remotely. (It is possible with a router with C2S VPN support, and Wake on LAN equipment, to establish a

virtual private network A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. The be ...

(VPN) connection with the router over the Internet if not connected to the

LAN Lan or LAN may also refer to: Science and technology * Local asymptotic normality, a fundamental property of regular models in statistics * Longitude of the ascending node, one of the orbital elements used to specify the orbit of an object in sp ...

, switch on a computer connected to the router, then connect to it.) Remote desktop products are available in three models: hosted service, software, and appliance. Tech support scammers use Remote Desktop software to connect to their victim's computer and will often Syskey the computer if the victim does not cooperate.

Protocols

Remote desktop protocols include the following: * Apple Remote Desktop Protocol (ARD) Original protocol for Apple Remote Desktop on macOS machines. * Appliance Link Protocol (ALP) a

Sun Microsystems Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the ...

-specific protocol featuring audio (play and record), remote printing, remote USB, accelerated video * HP Remote Graphics Software (RGS) a proprietary protocol designed by

Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...

specifically for high end workstation remoting and collaboration. * Independent Computing Architecture (ICA) a proprietary protocol designed by

Citrix Systems Citrix Systems, Inc. is an American multinational cloud computing and virtualization technology company that provides server, application and desktop virtualization, networking, software as a service (SaaS), and cloud computing technologies. C ...

* NX technology (NX) a proprietary protocol designed by NoMachine with open-source derivatives available from other forked projects. * PC-over-IP (PCoIP) a proprietary protocol used by VMware (licensed from Teradici) *

Remote Desktop Protocol Remote Desktop Protocol (RDP) is a proprietary protocol developed by Microsoft which provides a user with a graphical interface to connect to another computer over a network connection. The user employs RDP client software for this purpose, while t ...

(RDP) a Windows-specific protocol featuring audio and remote printing * Remote Frame Buffer Protocol (RFB) A framebuffer level cross-platform protocol that VNC is based on. * SPICE (Simple Protocol for Independent Computing Environments) – remote-display system built for virtual environments by

Qumranet Qumranet, Inc. was an enterprise software company offering a desktop virtualization platform based on hosted desktops in Kernel-based Virtual Machines (KVM) on servers, linked with their SPICE protocol. The company was also the creator, maintainer ...

, now

Red Hat Red Hat, Inc. is an American software company that provides open source software products to enterprises. Founded in 1993, Red Hat has its corporate headquarters in Raleigh, North Carolina, with other offices worldwide. Red Hat has become ass ...

Splashtop Splashtop is a family of remote-desktop software and remote support software, developed by Splashtop Inc. Splashtop enables users to remotely access or remotely support computers from desktop and mobile devices. Splashtop enables remote compu ...

a high performance remote desktop protocol developed by Splashtop, fully optimized for hardware (H.264) including Intel / AMD chipsets, NVIDIA / ATI GPU & APU, Qualcomm Snapdragon, and NVIDIA Tegra. By optimizing for different profiles of media codecs, Splashtop can deliver high frame rates with low latency, and also low power consumption. * Xpra a protocol originally developed for forwarding X11 application seamlessly with audio, video, remote printing, etc. - extended to support Windows and macOS servers * X Window System (X11) a well-established cross-platform protocol mainly used for displaying local applications; X11 is network-transparent * Wake-on-LAN a standard protocol for remotely waking up computers that are in low-power mode (turned off, but still have access to a power source).

Malicious variants

A (, sometimes called ) is a type of

malware Malware (a portmanteau for ''malicious software'') is any software intentionally designed to cause disruption to a computer, server, client, or computer network, leak private information, gain unauthorized access to information or systems, depri ...

that controls a system through a remote network connection. While desktop sharing and remote administration have many legal uses, "RAT" connotes criminal or malicious activity. A RAT is typically installed without the victim's knowledge, often as payload of a Trojan horse, and will try to hide its operation from the victim and from computer security software and other anti-virus software.

Notable examples

* PoisonIvy * Sub Seven * Beast Trojan * Bifrost *

Blackshades Blackshades is a malicious trojan horse used by hackers to control infected computers remotely. The malware targets computers using operating systems based on Microsoft Windows. According to US officials, over 500,000 computer systems have been in ...

DarkComet DarkComet is a remote access trojan (RAT) developed by Jean-Pierre Lesueur (known as DarkCoderSc), an independent programmer and computer security coder from France. Although the RAT was developed back in 2008, it began to proliferate at the sta ...

* Back Orifice * Back Orifice 2000 *Imminent Monitor * Havex

References