Remote Desktop Protocol (RDP) enables remote workers to access their work Windows workstations or servers from home. Many of the RDP servers used to help teleworkers are directly exposed to the Internet, and, when poorly configured, they expose the organization’s network to attacks. In the U.S. alone, the number of brute-force attacks against Internet-facing RDP services has increased from 200,000 per day in early-March to over 1,200,000 during mid-April.
Source: https://www.bleepingcomputer.com/news/security/rdp-brute-force-attacks-are-skyrocketing-due-to-remote-working/