In the mid February 2020, the National CERT published a recommendation advising all users to perform necessary regular monthly updates of their Microsoft OS. One of the critical points was about the discovered Microsoft Exchange vulnerabilty (CVE-2020-0688). Based on the available data, the National CERT would like to inform the public about the current massive abuse of the above vulnerabilty and recommend to all users to check if they updated their operating systems, i.e. applied available patches on time, so as to prevent further abuse of the detected vulnerabilities.