What is coin hive virus?

This is neither a virus nor a trojan, and it does not make the site unsafe to visit in any way whatsoever. Your antivirus package is crying wolf.

Coinhive is a Javascript plugin which implements a cryptocurrency miner. While you view a web site which uses this script, your browser will perform calculations to mine cryptocurrency for the owner of the web site.

Some users find this script annoying and inappropriate, as it will increase CPU usage (and, hence, power consumption) on your web browser while you have the web site open. However, this will end as soon as you leave the site.

The article is clear enough-- it is a JS library that mines Monero (cryptocurrency).

On legitimate sites, it's innocuous but annoying. But it has been bundled with (and thereby associated with) more than a few types of browser malware that force it to run on all sites and send the money back to the sole executor, which is why the AV is flagging it as bad-- thanks to AV logic, a hammer is just a tool until it's used in a murder, then going forward it assumes all hammers are murder implements.

The fact that your AV picked it up over the wire from its original source indicates this is likely a false positive. If it had found it buried in some app-data folder somewhere you should be concerned.