The extension that was impersonating vscode solidity (and many others following the same pattern) have been removed. We have seen that a fake extension or virus can spam many downloads (if that was their technique) So how to identify is the right extension? The best way is to look at the published date. The vscode solidity extension was published on the 2015-11-19 at 7:35 am, the published date cannot be faked. The extension was one of the first ones in the marketplace, after the official announcement of the extension sdk the day before. So in case of doubt, when choosing any extension.. check the date.