Two sharepoint groups that appear to be available to all users with modify rights

[KK20]

Our delightful cherubs have found access to two groups that I didnt know about. One is named "all company" and one named "community". My googlefu has shown that these are possibly Yammer groups. I could really to with getting rid of them but have no idea what they are for.

 

I can search for these sites from the root of my sharepoint and get:

 

Community goes to TENANT/portals/Community/default.aspx however, I get "An error occurred during the processing of /portals/Community/default.aspx. Code blocks are not allowed in this file." trying to visit this group

"All Company" goes to TENANT/sites/AllCompany.5243017.acdwrqrq/SitePages/Home.aspx and is a default site with "The new All Company group is ready"

 

All company shows up in sharepoint admin but community does not. I can access community by scraping the available sharepoint sites and linking to it. Users have read/write access to this (hence my desire to disable it)

 

Safe to delete? Where did they come from?

[KK20]

This proved to be fun. Yammer created the all company group. This was easy to remove as it wasnt needed. The community was a little different, this was created by the now defunct "Microsoft Office 365 video". This shut down on 1st March so there was no portal and seemingly no way to remove it. The GUI hides all the site collection sites so I needed to resort to powershell to get rid of that one.