A research paper published at the start of the month estimates that Coinhive, a service for in-browser cryptocurrency mining, often abused by cyber-criminals, is making around a quarter of a million US dollars per month in mined Monero.
The stats were compiled by four academics from the RWTH Aachen University in Aachen, Germany.
Researchers say they analyzed all the .com, .net, and .org domains in the Alexa Top 1 Million most popular sites on the Internet. They also used a new method that unearthed more sites involved in in-browser cryptocurrency mining compared to tools currently available on the market.
RWTH Aachen researchers say that Coinhive is by far the leader among all in-browser mining services, with a market share of 75% or higher.
The number is consistent with figures documented by Troy Mursch, a security researcher who's been tracking Coinhive's evolution since its launch in September 2017.
But the service's dominance may not last for long. Today, Mursch published new numbers showing that Coinhive has been slowly losing market share to many of its rivals.
Most of the sites running in-browser miners were adult and gaming sites. These results are consistent with a Qihoo 360 report from February 2018, where adult and gaming were also two of the most popular categories of sites found to run in-browser mining scripts (also referred to as cryptojackers).
Researchers also added that Coinhive's massive scale also contributes 1.18% of mined blocks to the entire Monero network, which is quite the market share just for one service among the plethora of mining pools and competing in-browser mining services.
But $250,000/month is not really that of a big sum when divided among the Coinhive service and all of its customers.
Coinhive gets to keep a 30% cut of all the mined funds, which equates to around $75,000 a month. The rest is then split among Coinhive's hundreds or thousands of customers. What's left is not that much.
"While probably profitable for Coinhive, it remains questionable whether mining is a feasible alternative to ads," the research team said in their paper, entitled "Digging into Browser-based Crypto Mining."
Note: The research team also looked at one of Coinhive's lesser-known features —its URL shortening service. This service works by asking users to wait while Coinhive mines a small piece of Monero inside their browsers, and at the end of a timer, redirecting users to the long, original URL. Researchers found that ten users were responsible for creating roughly 85% of all the Coinhive short links, which means the feature is not that popular as initially believed.