As you may know, there has been more and more threats using Microsoft Teams as communication channel.
While Microsoft has already had quite few security features to protect you against threats using Teams – such as message preview for unknown sender or more recently blocking ability for sending message from trial tenant (see Teams – You can now block federation with trial tenants), Microsoft just introduced a new security feature meetings hosted with Teams.
This new security feature requires a Captcha code to be provided when participants are joining either from untrusted organization or as anonymous (it is recommended to have this option disabled).
To enable this option, connect as Teams administrator to your Teams tenant to access the Meeting policies (interface may be different depending if you are using the new administration experience or the classic)
- Classic experience
Access the Meetings\Meeting policies blade and edit the policy you want to enable the Captcha option to enable the Require a verification check from
- New experience
Access the Settings & policies\Meetings blade and edit the policy you want to enable the Captcha option to enable the Require a verification check from
Once enabled, the next time an anonymous/untrusted participant is joining a meeting, he will be asked to provide a Captcha code to validate it’s not a robot – this includes joining the lobby if enabled
NOTE this option is disabled by default