Coinhive and Cryptojacking
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Summary
Threat details
Cryptojacking is a method of hijacking a machine or web browser to mine for cryptocurrency. This activity is performed without a user’s knowledge or permission. A successful attack does not require the user to install any software, as it works within the web browser directly.
Much of this traffic is known as ‘in-browser mining’ and is hosted on a web site. The mining script is executed when the user browses to the site. There has been an increase in attackers using ‘pop-ups’ and ‘pop-unders’ in order to maintain mining when the user has left the site.
cryptojacking isn’t limited to just web browsers, it is possible for cryptojacking malware to infect the host (Windows, Linux and macOS), in addition to iOS and Android phones.
Browser extensions have also been identified as using JavaScript to mine cryptocurrency (ArchivePoster and Iridium, for example).
A tale-tell sign of a cryptojacking infection is a significant reduction in host machine performance, as the CPU and graphics cards are used for cryptomining.
The following is a link to a PowerShell script that monitors CPU usage across a provided list of hosts. This script can be used to provide email alerts for hosts with high CPU usage, indicative of a cryptominer in use.
For further information:
Remediation advice
If you suspect that your machine/browser is being cryptojacked:Remediation steps
Last edited: 17 February 2020 11:29 am