The recently patched vulnerabilities in Microsoft Exchange have sparked new interest among cybercriminals, who increased the volume of attacks focusing on this particular vector. The company saw a 53% swell in the number of organizations affected by the wormable WannaCry ransomware. Check Point observed the same trend starting in December 2020, with attacks continuing to increase well over 12,000 in March 2021. The figures show the importance of patching on time, else organizations remain vulnerable to attack vectors that should be mostly extinct.
Source: https://www.bleepingcomputer.com/news/security/microsoft-exchange-attacks-increase-while-wannacry-gets-a-restart/