Anyway, I hope the author can be a bit more specific about what actually has happened to those unlucky enough to have received these malicious updates. And perhaps a tool to e.g. do a checksum of all Notepad++ files, and compare them to the ones of a verified clean install of the user's installed version, would be a start? Though I would assume these malicious updates would be clever enough to rather have dropped and executed additional files, rather than doing something with the Notepad++ binaries themselves.
And I agree with another comment here. With all those spelling mistakes that notification kind of reads like it could have been written by a state-sponsored actor. Not to be (too) paranoid here, but can we be sure that this is the actual author, and that the new version isn't the malicious one?
Did I understand the attack wrongly? The software could have a 100% correct checksum, because the attack happened in a remote machine that deals with call home events from Notepad++, I guess one of those "Telemetry" add-ons. The attackers did a MITM to Notepad++ traffic.
However, there are ways around this, too. No solution is perfect.