Over 20,000 vulnerable Microsoft Exchange servers exposed to attacksTens of thousands of Microsoft Exchange email servers in Europe, the U.S., and Asia exposed on the public internet are vulnerable to remote code execution flaws. [...]
Source: Over 20,000 vulnerable Microsoft Exchange servers exposed to attacks (https://www.bleepingcomputer.com/news/security/over-20-000-vulnerable-microsoft-exchange-servers-exposed-to-attacks/)