Internet-Security.com UDP port 1029 details

Legacy Microsoft Windows (Windows 2000/XP/Server 2003) RPC services often used dynamically assigned high ports, and UDP 1029 was commonly seen as one of these endpoints.
In practice, the Windows Messenger Service (“net send” pop-ups) traffic was frequently observed on UDP ports 1026–1029, including 1029, due to RPC’s dynamic port assignment on those systems.
This port saw widespread abuse in 2003–2004 by “Messenger Service spam,” where unsolicited UDP messages to 1026–1029 triggered pop-up ads; many admins blocked these ports to mitigate the issue.

UDP 1029