Variant/Dropper of the OSX/Proton malware posing as a fictitious 'Symantec Malware Detector' application and being distributed by a fake Symantec blog [1]. OSX/Proton is a persistent Backdoor and Remote Access Trojan (RAT) that exfiltrates user data including passwords and browsing information [2].

References:

1. https://blog.malwarebytes.com/threat-analysis/mac-threat-analysis/2017/11/osx-proton-spreading-through-fake-symantec-blog/
2. https://www.cybersixgill.com/proton-a-new-mac-os-rat/