Microsoft Exchange Server Breach

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The Microsoft Exchange Server breach began in January 2021 when four zero-day vulnerabilities were exploited by attackers, including the state-sponsored group Hafnium. These vulnerabilities allowed attackers to gain full access to user emails, passwords, and administrator privileges on affected servers. The breach affected over 30,000 U.S. businesses and numerous organizations worldwide, including local governments and financial institutions. Attackers installed backdoors, enabling continued access even after patches were applied. Microsoft released patches on March 2, 2021, but many servers remained unpatched, leaving them vulnerable to further exploitation. The breach led to the deployment of ransomware and other malware, posing significant risks to data security. The incident highlighted the challenges faced by small and medium-sized businesses in securing against cyber threats. Despite efforts to mitigate the vulnerabilities, the breach remains a critical cybersecurity event due to its widespread impact and potential for future exploitation.