That's a wallet compiled by an original dev, as you can see from checksums in a web archive.
We believe these are false alerts, as this wallet is in use since 2014, but if you don't trust it, use
https://play.google.com/store/apps/details?id=com.coinspot.mobileCheck this:
https://web.archive.org/web/20140705185938/http://download.mooncoin.info/It is the original download-page of the latest wallet 1.862.1, that is still in use - archived by Internet Archive Wayback Machine. You can check your download from the place you mentioned with a hashcheck-tool like
http://code.kliu.org/hashcheck and compare. If you get the same hashes as results, then it should be the same original Mooncoin-wallet.
On the archived original page of mooncoin.info you can also find information about the warnings.
You can also check for mooncoin.rocks in the Web Archive.