OSX/Leverage is a malware OS X Backdoor with command and control capabilities. It poses as a legitimate software installer (e.g. Adobe Flash) [1]. It was originally discovered in 2013 and has resurfaced in 2017 with ties to the Syrian Electronic Army [2].

References:

1. https://www.intego.com/mac-security-blog/apple-updates-xprotect-to-block-new-leverage-malware-variant/
2. http://www.thesafemac.com/tag/leverage/