The backdoor was found in nssock2.dll 5.0.0.26, which was modified on July 13, 2017. It is a dependent component required by Xshell and related products.
The backdoor module lurks in the nssock2.dll library that has a valid signature within Xshell software suites. On August 7, 2017, NetSarang stated that backdoors were discovered in the following product versions that were released on July 18: Xshell manages remote servers based on SSH, Telnet, and other protocols.Xshell and other programs provide secure connectivity solutions to manage Linux servers on Windows platforms. Some SSH implementations include both server and client implementations and support custom non-standard authentication algorithms not listed in this table.Xshell is a remote connectivity program developed by NetSarang, which also provides Xmanager and Xftp. This table lists standard authentication key algorithms implemented by SSH clients.
Portable version can be download from Win32-OpenSSH for other versions.
Win32-OpenSSH can be installed as an optional component in the Windows versiones before Windows 10 version 1803 to Windows 10 version 1709. ^ Included and enabled by default since windows 10 version 1803.^ lsh supports only one BSD platform officially, FreeBSD.The list is not exhaustive, but rather reflects the most common platforms today. Partial indicates that while it works, the client lacks important functionality compared to versions for other OSs but may still be under development.The operating systems or virtual machines the SSH clients are designed to run on without emulation include several possibilities: