Microsoft provides the client required for connecting to newer RDP versions for downlevel operating systems.
[clarification needed] Based on the ITU-T T.128 application sharing protocol (during draft also known as "T.share") from the T.120 recommendation series, the first version of RDP (named version 4.0) was introduced by Microsoft with "Terminal Services", as a part of their product Windows NT 4.0 Server, Terminal Server Edition.
[1] The Terminal Services Edition of NT 4.0 relied on Citrix's MultiWin technology, previously provided as a part of Citrix WinFrame atop Windows NT 3.51, in order to support multiple users and login sessions simultaneously.
The T.128 application sharing technology was acquired by Microsoft from UK software developer Data Connection Limited.
[6] This version was introduced with Windows 2000 Server, added support for a number of features, including printing to local printers, and aimed to improve network bandwidth usage.
This version was introduced with Windows Server 2003, included support for console mode connections, a session directory, and local resource mapping.
[10] In addition to changes related to how a remote administrator connects to the "console",[11] this version has new functionality introduced in Windows Server 2008, such as connecting remotely to individual programs and a new client-side printer redirection system that makes the client's print capabilities available to applications running on the server, without having to install print drivers on the server[12][13] also on the other hand, remote administrator can freely install, add/remove any software or setting at the client's end.
This version has new functions such as Windows Media Player redirection, bidirectional audio, multi-monitor support, Aero glass support, enhanced bitmap acceleration, Easy Print redirection,[16] Language Bar docking.
Most RDP 7.0 features like Aero glass remote use, bidirectional audio, Windows Media Player redirection, multiple monitor support and Remote Desktop Easy Print are only available in Windows 7 Enterprise or Ultimate editions.
[22] After installing the updates, for the RDP 8.0 protocol to be enabled between Windows 7 machines, an extra configuration step is needed using the Group Policy editor.
The Aero Glass remoting feature (applicable to Windows 7 machines connecting to each other) has also been removed in RDP 8.
[29] Version 10.0 of the RDP was introduced with Windows 10 and includes the following new features: AutoSize zoom (useful for HiDPI clients).
[33][34] RDP sessions are also susceptible to in-memory credential harvesting, which can be used to launch pass the hash attacks.
No immediate malicious exploitation followed, but experts were unanimous that this was likely, and could cause widespread harm based on the number of systems that appeared to have remained exposed and unpatched.
In addition to the Microsoft-created Remote Desktop Services, open-source RDP servers on Unix include FreeRDP (see above), ogon project and xrdp.
By default, Microsoft's RDP server refuses connections to user accounts with empty passwords (but this can be changed with the Group Policy Editor[44]).
[46][47] These compromised RDPs may be used as a "staging ground" for conducting other types of fraud or to access sensitive personal or corporate data.
[48] Researchers further report instances of cybercriminals using RDPs to directly drop malware on computers.