WHY HAS MICROSOFT BEEN ROUTING EXAMPLE.COM TRAFFIC TO A COMPANY IN JAPAN?

Summary from the TLDR InfoSec newsletter

Microsoft's autodiscover service was found routing email traffic for example.com—a domain reserved for testing under RFC2606—to subdomains belonging to Sumitomo Electric in Japan, potentially causing test credentials to be sent outside Microsoft's network. The misconfiguration, which may have persisted for five years, has been suppressed, but Microsoft has not explained how the Japanese company's servers were added to its network configuration. The incident raises concerns about other potential misconfigurations following Microsoft's 2024 breach, where forgotten test account privileges enabled Russian state hackers to monitor executive emails.