Adam Carbonell has created a non-malicious extension, called "Get CRX": https://chrome.google.com/webstore/detail/get-crx/dijpllakibenlejkbajahncialkbdkjc
Google has removed the original extension, along with several other extensions with similar malware.
Relavant links:
- Japanese writeup: https://translate.google.com/translate?sl=ja&tl=en&js=y&prev=_t&hl=ja&ie=UTF-8&u=https%3A%2F%2Fgist.github.com%2Fmala%2Fe87973df5029d96c9269d9431fcef5cb&edit-text=&act=url
- Reddit thread (a few days after this): https://www.reddit.com/r/chrome/comments/5arx3l/live_http_headers_extension_hijacked/