Sensors reporting firewall logs detected a significant increase in scans for port 8530/TCP and 8531/TCP over the course of last week. Some of these reports originate from Shadowserver, and likely other researchers, but there are also some that do not correspond to known research-related IP addresses.

SANS Stormcast Monday, November 3rd, 2025: Port 8530/8531 Scans; BADCANDY Webshells; Open VSX Security Improvements
Scans for WSUS: Port 8530/8531 TCP, CVE-2025-59287 We did observe an increase in scans for TCP ports 8530 and 8531. These ports are associated with

