Editing Microsoft Exchange Server (section)

===2021===
{{Main|2021 Microsoft Exchange Server data breach}}
In 2021, critical [[Zero-day (computing)|zero-day]] exploits were discovered in Microsoft Exchange Server.<ref>{{Cite web|date=2021-03-02|title=HAFNIUM targeting Exchange Servers with 0-day exploits|url=https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers/|access-date=2021-03-14|website=Microsoft Security|language=en-US}}</ref> Thousands of organizations have been affected by hackers using these techniques to steal information and install malicious code.<ref>{{Cite news|date=2021-03-11|title=Exchange email hack: Hundreds of UK firms compromised|language=en-GB|work=BBC News|url=https://www.bbc.com/news/technology-56365372|access-date=2021-03-12}}</ref> Microsoft revealed that these vulnerabilities had existed for around 10 years,<ref name=2021hackcnbc/> but were exploited only from January 2021 onwards. The attack affected the email systems of an estimated 250,000 global customers, including state and local governments, policy think tanks, academic institutions, infectious disease researchers and businesses such as law firms and defense contractors.<ref name=2021hackcnn/>

In a separate incident, an ongoing [[Brute-force attack|brute-force]] campaign from mid-2019 to the present (July 2021){{Update inline|date=November 2023|reason=2 years later since updated, still says this is ongoing}}, attributed by [[National Cyber Security Centre (United Kingdom)|British]] and American ([[National Security Agency|NSA]], [[Federal Bureau of Investigation|FBI]], [[Cybersecurity and Infrastructure Security Agency|CISA]]) security agencies to the [[GRU (Russian Federation)|GRU]], uses/used publicly known Exchange vulnerabilities, as well as already-obtained account credentials and other methods, to infiltrate networks and steal data.<ref>{{cite web |url=https://www.nsa.gov/news-features/press-room/Article/2677750/nsa-partners-release-cybersecurity-advisory-on-brute-force-global-cyber-campaign/ |title=NSA, Partners Release Cybersecurity Advisory on Brute Force Global Cyber Campaign |website=nsa.gov |publisher=[[National Security Agency]] |access-date=July 2, 2021 |archive-date=July 2, 2021 |archive-url=https://web.archive.org/web/20210702002139/https://www.nsa.gov/news-features/press-room/Article/2677750/nsa-partners-release-cybersecurity-advisory-on-brute-force-global-cyber-campaign/ |url-status=dead }}</ref><ref>{{cite web |url=https://media.defense.gov/2021/Jul/01/2002753896/-1/-1/1/CSA_GRU_GLOBAL_BRUTE_FORCE_CAMPAIGN_UOO158036-21.PDF |title=Russian GRU Conducting Global Brute Force Campaign to Compromise Enterprise and Cloud Environments |website=Defense.gov |publisher=Joint publication form US/UK security agencies |access-date=July 3, 2021}}</ref>