You can find here the
VirusTotal detection rate of the malicious file.
This type of file has been around since September this year. The attacker was able to compromise the site and use it to mine bitcoin for him. Upon reverse lookup, the site is hosted on a reputable web hosting company. The same IP was also hosting more than 1,000 domains and might also be suffering high CPU usage during bitcoin mining.
We were able to clean the infection and restore a healthy working site for the client. If you want to know more about IoC (Indicator of Compromise),
SANS.org published a paper about it.