Turla Cyber Espionage Group’s 5-year campaign hit three targets over five years, ESET warns. Turla, an advanced persistent threat group with suspected ties to the Russian government, exploited malware called LightNeuron to gain access to Exchange servers. The malware takes advantage of the Transport Agent functionality of Microsoft Exchange, which acts as a plug-in system for the Exchange server. The attackers also had the ability to compose new emails and send them under the names of legitimate users, the research shows.”]
Source: https://www.cuinfosecurity.com/researchers-spies-exploit-microsoft-exchange-backdoor-a-12459