Handler on Duty: Brad Duncan
Threat Level: green
Podcast Detail
DNS Debugging; MSFT Zero Trust DNS; MSFT Graph API Abuse
If you are not able to play the podcast using the player below: Use this direct link to the audio file: https://traffic.libsyn.com/securitypodcast/8968.mp3
My Next Class
Click HERE to learn more about classes Johannes is teaching for SANS
DNS Debugging with nslookup
https://isc.sans.edu/diary/nslookups+Debug+Options/30894/
Microsoft Plans DNS Lockdown
https://techcommunity.microsoft.com/t5/networking-blog/announcing-zero-trust-dns-private-preview/ba-p/4110366
Microsoft Graph API Abuse
https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/graph-api-threats
SANSFIRE SEC522 Defending Web Applications
https://www.sans.org/cyber-security-training-events/sansfire-2024/
https://isc.sans.edu/diary/nslookups+Debug+Options/30894/
Microsoft Plans DNS Lockdown
https://techcommunity.microsoft.com/t5/networking-blog/announcing-zero-trust-dns-private-preview/ba-p/4110366
Microsoft Graph API Abuse
https://symantec-enterprise-blogs.security.com/blogs/threat-intelligence/graph-api-threats
SANSFIRE SEC522 Defending Web Applications
https://www.sans.org/cyber-security-training-events/sansfire-2024/
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All outgoing traffic from any devices other than these resolvers to ports 53 or 853 is blocked. The resolvers connect only to specific upstream DNS servers with DNS over TLS and verified using DNSSEC. So there is no traffic leaving the network on port 53. The only outgoing traffic on 853 is to a specific list of servers. The objective here is to be able to audit all internal DNS requests.
The problem is DNS over HTTPS. In an effort to restrict this, I have blocked port 443 to a list of known DNS servers. But this is a moving target.
Any suggestions for either a regularly updated list of common DNS severs or a better way to block DNS over HTTPS?