Addition of new meta-categories

[geekscrapy]

There are quite a few objects in the meta-category misc list at the moment. These should be split further into other category types before this list gets huge!

For starters, I propose the following new meta-categories:

• artifact - for the likes of the objects defined within: https://github.com/ForensicArtifacts/artifacts/tree/master/data
• rule - At the moment this would contain yara, suricata. We have also internally created a snort object among other rule based types. This is mainly regarding attributes that are able to be applied directly to a detection engine as is, with no additional processing.
• external - This would cover the likes of the virustotal, cortex, cuckoo and fail2ban, enrichment type objects, where all elements of the object are related directly

[haxpak]

The meta categories can be changed from the definition.json When a meta category is changed, the MISP framework automatically accepts the new category in the add object. @geekscrapy you could change them in your fork and create a pull request for the maintainers to review

[geekscrapy]

Thanks, I didn't want to assume they could just be created 😀 but that's good to know. Await a pull request....