List of Internet scanner IPs by organization
Created leveraging SANS research data feed and sponsored by our friends at ASNLookup.com
Point your security product/firewall to the following URL as an external threat feed/IP list.
Stretchoid.txt example:
https://raw.githubusercontent.com/Xorlent/Internet-Scanners/main/stretchoid.txt
If your appliance or program does not correctly interpret Windows CR/LF, you can post-process the list with (thanks @jlongua):
sed -i "s/\r//g" stretchoid.txt