You can breathe a sigh of relief. If you got a weird Windows 7 update notification from Microsoft last night, it might have thrown you. Even help forums were freaking out about a possible hack at Microsoft.
The reason for the panic was some of the information in the update notification. One URL had a .GOV domain and started with the letters 'HCK,' and the notification looked like it was an official Microsoft alert.
Luckily, it was all a misunderstanding. Microsoft announced, "We incorrectly published a test update and are in the process of removing it." There was actually no update to install anyway, so it's all harmless in the end.
Windows 7 is still fully supported by Microsoft, since many users don't like Windows 8 and Windows 10. So it's entirely possible Microsoft will send out Windows 7 update notifications in the future. And for now, you can rest assured that Microsoft wasn't hacked this time, and any upcoming updates should be safe as well.