It is a little over a week since Microsoft Exchange email servers were attacked by a group which Microsoft as described as a network of hackers it calls Hafnium. It is not clear who these people are, but the attack, which impacted as many as 60,000 companies â and by some estimates 100,000 â has forced Microsoft to release out of-band emergency patches for Exchange Server 2013, Exchange Server 2016, and Exchange Server 2019. Exchange Attack Spreading? The situation is so bad, in fact, that Microsoft has also released updates for older, unsupported versions of Exchange to deal with the four newly discovered security vulnerabilities (Microsoft also made it clear that it was only patching these vulnerabilities and that these older versions will remain unsupported after this has passed.)