The free-of-charge ‘PuTTY’ application at this link is published and maintained by us. The copy there is the latest release, usually updated within a few days of us publishing it on our own website.
There have been other copies of PuTTY on the store, some looking quite similar, and some charging money. Those were uploaded by other people, and we can't guarantee anything about them.
The first version we published to the Microsoft Store was 0.76 (some time after its initial release on our website).