I have noticed a surge in probe against the RDP service in the past 2 weeks. In August, a remote code execution (RCE) critical patch was released to fix an exploit related to CVE-2021-34535 which include a POC to exploit this vulnerability. This vulnerability is also affecting Microsoft Hyper-V Manager “Enhanced Session Mode” [5] and Microsoft Defender’s Application Guard (WDAG) [6].
Article Link: InfoSec Handlers Diary Blog