If such letters came to you - a reason to be wary!
The only way to protect yourself at the moment is to register a new unknown e-mail address and change it via Skype site
The main e-mail account for a new one.
It is impossible to change the main e-mail through skype itself! Only through the site!
Over the last week, 10 people from my contact list were hacked using this vulnerability.
I want to warn everyone to protect themselves as quickly as possible, since so far Microsoft has not taken any action, take care of your own security.
There was a way (PoC) how to use the vulnerability: http://forum.xeksec.com/f13/t68922/#post98725
Official comment from a Skype representative:
We have received Skype security vulnerability reports. For the security of our users, we have temporarily disabled the password reset function, and we continue to investigate this issue further. We apologize for the inconvenience, the safety of our users is our top priority.
It would not be superfluous for your friends to find out this information, share the article with them!