Replace DNS0 analyzers with DNS4EU

[mlodic]

Unluckily the DNS0 service has been discontinued. We should remove the related analyzers and add, in place of those, add an integration to the new DNS4EU service.

We should use the "unfiltered resolution" for DNS resolutions so we don't get blocked, while we should use the "protective resolution" to check whether a domain is known to be malicious or not.

[Gargee61]

@mlodic Hi! Can i work on this issue ?

[mlodic]

you are already assigned to another issue, please take care of this as guidelines rules want

[Gargee61]

My bad! Since I've already completed the work for issue #3146 and submitted PR #3161 I'd love to work on this issue (#3154) next. Would it be okay to proceed once my current PR for #3146 is reviewed/merged?

[mlodic]

you don't have to hurry, please finish your current assignment properly before asking a new one.

[Rutuja123-dos]

Hi @mlodic, I'm interested in contributing to IntelOwl for GSoC 2026. I recently worked on API documentation and state-vector logic for an Apache-related project (QuMat), and I am comfortable with Python. So let me know if anyone is working on this issues

[Rutuja123-dos]

Thank you for the assignment, @fgibertoni! I am starting work on the DNS4EU analyzer now. I will reach out if I have any specific questions regarding the API implementation. Excited to contribute

[NikhilRaikwar]

Hi @mlodic,

I would like to work on this issue. I understand the requirements and have a clear plan:

1. Cleanup: Remove the discontinued DNS0 analyzers and tests.
2. Resolver: Implement DNS4EUResolver using the unfiltered endpoint (https://unfiltered.joindns4.eu/dns-query) to ensure we don't get blocked.
3. Malicious Detector: Implement DNS4EUMaliciousDetector using the protective endpoint (https://protective.joindns4.eu/dns-query) to check for malicious domains.
4. Backend: Add the necessary migrations (remove old/add new configs) and unit tests.

Please assign this to me. I'm ready to start immediately.