A Russian supported APT has been exploiting vulnerabilities in mail servers.

The Russian backed APT 28 has been found to be exploiting vulnerabilities in mail servers to target government organizations. France has accused the group of carrying out attacks in the past several weeks. The group has made us of XSS exploits to breach the servers.

Read more:

https://www.securityweek.com/russian-apt-exploiting-mail-servers-against-government-defense-organizations/