Threat actors are now actively scanning for the Microsoft Exchange ProxyShell remote code execution vulnerabilities after technical details were released at the Black Hat conference. The vulnerabilities were discovered by researcher Orange Tsai, whose team received a $200,000 prize for their use in April’s Pwn2Own 2021 hacking contest. Attackers modified their scans to use the new Autodiscover URL disclosed in Tsai’s slide above. Security researchers PeterJson and Jang published an article providing technical information about how they could successfully reproduce the ProxyShell exploit.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-exchange-servers-scanned-for-proxyshell-vulnerability-patch-now/