German Cloud Service Provider Hacked

December 7, 2023


The hosted exchange of the German provider United Hoster suffered a ransomware attack on Saturday (May 20th). "As part of an internal investigation, it was determined that an attacker exploited an unknown vulnerability in Microsoft Exchange to gain access to the Exchange Server," a company spokesman told heise online

United Hoster is building a new Microsoft Exchange environment into which customers will eventually be migrated so that they can receive the full range of functions again. The company does not provide information about the number of affected customers or mailboxes, as this is a business secret. It is also unclear when United Hoster expects to restore services in the new structure. The company spokesman did not specify which Exchange security gap the attackers were able to abuse.

Incident Date

May 20, 2023


Estimated Cost

hosted exchange offline, services expected to be restored in new MS environment, undisclosed number of customers affected.

Type of Malware

No Malware identified

Threat Source

No threat source identified