Monero has been one of the best coins used for crypto-jacking malware and ransomware for a while now because of Monero's high privacy features.
According to Justin Ehrenhofer, the director of the Malware Response Workgroup, has stated that the two main factors that make XMR attractive to hackers are:
“Attackers like Monero for two reasons: 1) it is private, so they do not need to worry about companies and law enforcement tracing what they do with the Monero after they mine it, and 2) Monero uses a Proof of Work (PoW) algorithm that is CPU and GPU-friendly; thus, the infected machines are competitive. These two components are increasingly distinguishing factors for why attackers choose to mine Monero over other cryptocurrencies.”
While it is still possible to introduce malware on another person's computer for mining Bitcoin and other digital currencies, the XMR privacy features make it stand out as one of the best choices.
"The new Malware Response website seeks to inform visitors on the ways to prevent and remove malware. As stated, it’s expected that visitors will land on the site frustrated and seeking answers, since most do not understand what is happening," CCN.
There have been apps out there that have been developed in order to allow website owner's to opt-in, so that their browsers will mine XMR while they used the website and to be able to do this instead of showing advertisments, even though to me this feels like stealing.
However, it is also for hackers to inject mining scripts into vulnerable websites without the website owner or users having any idea, aka "cryptojacking."
McAfee labs has also said that cryptojacking has increased by 86% in the second quarter of 2018, and is up by 459% this year thanks to a leak from the NSA's hacking tools.
Monero has said that they are strongly against supporting any unwelcomed cryptojacking or other forms of mining on another person's computer, and are finally taking steps to prevent such a thing as this from continuing by allowing users to educate themselves on the different resources hackers can use to bypass their hardware or operating system.
https://ww.getmonero.org/2018/09/26/Introducing-the-Monero-Malware-Response-Workgroup-Website.html