Barry Feigenbaum originally designed SMB at [[IBM]] in early 1983 with the aim of turning [[DOS]] [[INT 21h]] local file access into a networked file system.<ref name='tridgemyths'>{{cite web|url=https://www.samba.org/samba/docs/myths_about_samba.html|title=Myths About Samba|author=Tridgell, Andrew|author-link=Andrew Tridgell|access-date=January 3, 2016|archive-hurlurl=https://web.archive.org/web/20171020045502/https://www.samba.org/samba/docs/myths_about_samba.html|archive-date=October 20, 2017|url-status=live}}</ref> [[Microsoft]] made considerable modifications to the most commonly used version and included SMB support in the [[LAN Manager]] operating system it had started developing for [[OS/2]] with [[3Com]] around 1990.<ref name="thereggistertheregister/2018/06/08/smb1">{{cite news |last1=Speed |first1=Richard |title=Have to use SMB 1.0? Windows 10 April 2018 Update says NO |url=https://www.theregister.com/2018/06/08/windows_10_smb1/ |access-date=18 February 2023 |work=[[theregister.com]] |language=en}}</ref><ref name="borncity/2017/06/15/retire-smbv1">{{cite news |author1=guenni |title=Microsoft plans to deactivate SMBv1 in Windows 10 V1709 |url=https://borncity.com/win/2017/06/15/microsoft-plans-to-retire-smbv1-in-fall-in-windows-10/ |access-date=18 February 2023 |work=Born's Tech and Windows World |date=15 June 2017}}</ref><ref name="thurrott/265909">{{cite news |last1=Giret |first1=Laurent |title=Microsoft Gets Ready to Disable SMB1 Protocol on Windows 11 |url=https://www.thurrott.com/windows/265909/microsoft-gets-ready-to-disable-smb1-protocol-on-windows-11 |access-date=18 February 2023 |work=Thurrott.com |date=20 April 2022}}</ref> Microsoft continued to add features to the protocol in [[Windows for Workgroups]] ({{circa|1992}}) and in later versions of Windows. LAN Manager authentication was implemented based on the original legacy SMB specification's requirement to use IBM "LAN Manager" passwords, but implemented [[Data Encryption Standard|DES]] in a [[LM hash#Security weaknesses|flawed manner]] that allowed passwords to be cracked.<ref>{{cite web|author=Christopher Hertel|year=1999|title=SMB: The Server Message Block Protocol|url=http://ubiqx.org/cifs/SMB.html|url-status=live|archive-url=https://web.archive.org/web/20100310140946/http://ubiqx.org/cifs/SMB.html|archive-date=March 10, 2010|access-date=November 1, 2009}}</ref> Later, [[Kerberos (protocol)|Kerberos]] authentication was also added. The [[Windows ___domain]] logon protocols initially used [[40-bit encryption]] outside of the [[United States]], because of export restrictions on stronger 128-bit encryption<ref>{{cite web|date=November 1, 2006|title=Description of Microsoft Windows Encryption Pack 1|url=http://support.microsoft.com/kb/159709|url-status=live|archive-url=https://web.archive.org/web/20091002075623/http://support.microsoft.com/kb/159709|archive-date=October 2, 2009|access-date=November 1, 2009|publisher=[[Microsoft]]}}</ref> (subsequently lifted in 1996 when President [[Bill Clinton]] signed [[Executive Order 13026]]<ref>{{cite web|year=1996|title=US Executive Order 13026|url=http://www.gpo.gov/fdsys/pkg/WCPD-1996-11-18/pdf/WCPD-1996-11-18-Pg2399.pdf|url-status=live|archive-url=https://web.archive.org/web/20091010125029/http://www.gpo.gov/fdsys/pkg/WCPD-1996-11-18/pdf/WCPD-1996-11-18-Pg2399.pdf|archive-date=October 10, 2009|access-date=November 1, 2009|publisher=[[United States Government]]}}</ref>).
SMB 1.0 (or SMB1) was originally designed to run on [[NetBIOS Frames]] (NetBIOS over [[IEEE 802.2]]). Since then, it has been adapted to NetBIOS over [[IPX/SPX]] (NBX), and [[NetBIOS over TCP/IP]] (NetBT). Also, since [[Windows 2000]], SMB runs on [[Transmission Control Protocol|TCP]] using TCP port 445, a feature known as "direct host SMB".<ref name="direct">{{cite web|url=http://support.microsoft.com/kb/204279|title=Direct hosting of SMB over TCP/IP|date=October 11, 2007|publisher=[[Microsoft]]|access-date=November 1, 2009|archive-url=https://web.archive.org/web/20110326164716/http://support.microsoft.com/kb/204279|archive-date=March 26, 2011|url-status=live}}</ref> There is still a thivnthin layer (similar to the Session Message packet of NetBT's Session Service) between SMB and TCP.<ref name="direct" /> Windows Server 2003, and legacy [[Network-attached storage|NAS]] devices use SMB1 natively.
SMB1 is an extremely chatty protocol, which is not such an issue on a [[local area network]] (LAN) with low latency. It becomes very slow on [[Wide area network|wide area networks]] (WAN) as the back and forth handshake of the protocol magnifies the inherent high latency of such a network. Later versions of the protocol reduced the high number of handshake exchanges. One approach to mitigating the inefficiencies in the protocol is to use [[WAN optimization]] products such as those provided by [[Riverbed Technology|Riverbed]], [[Silver Peak Systems|Silver Peak]], or [[Cisco Systems|Cisco]]. A better approach is to upgrade to a later version of SMB. This includes upgrading both NAS devices as well as Windows Server 2003. The most effective method to identify SMB1 traffic is with a network analyzer tool, such as [[Wireshark]]. Microsoft also provides an auditing tool in [[Windows Server 2016]] to track down devices that use SMB1.<ref name="messageanalyzer">{{cite web |last1=Kyttle |first1=Ralph |title=SMB1 – Audit Active Usage using Message Analyzer |url=https://blogs.technet.microsoft.com/ralphkyttle/2017/05/13/smb1-audit-active-usage-using-message-analyzer/ |website=Microsoft TechNet |publisher=Microsoft |access-date=28 March 2019 |date=13 May 2017 |archive-url=https://web.archive.org/web/20190328223802/https://blogs.technet.microsoft.com/ralphkyttle/2017/05/13/smb1-audit-active-usage-using-message-analyzer/ |archive-date=March 28, 2019 |url-status=live }}</ref>
