Internet users in Vietnam are being warned of a malicious software program hiding on websites to ‘steal’ the computing resources on visitors’ devices to mine the cryptocurrency Monero for hackers.

The Vietnam Computer Emergency Response Team (VNCERT) announced on Thursday that it has received numerous complaints over the past week of cybersecurity threats caused by the CoinHive malware program.

Monero, like Bitcoin, is a digital currency where coins are ‘mined’ by using computing power to solve puzzles and problems in the cryptocurrency’s systems.

CoinHive is a JavaScript program that lurks unseen on websites in order to tap into the processing power of visitors' computers and mine Monero.

When a visitor accesses a website infected with CoinHive, the malicious program is able to secretly run on the victim’s Internet browser and solve problems to earn Monero. The mined coins are then transferred directly to the hackers’ ‘wallet’.

The process taps into the computer’s CPU power, chips, or graphics cards on the ‘borrowed PC.”  It also causes the victim’s computer to consume more electricity and runs up a higher power bill.

A man carries out a transaction on a Bitcoin machine in Vietnam. Photo: Tuoi Tre

VNCERT has initiated an emergency response to tackle the malware and introduced a set of recommendations for Internet users to protect themselves, according to deputy director Ngo Khac Lich.

Webmasters are advised to ensure their websites have not been infected by the malware, whereas Chrome users are recommended to install “No Coin Chrome” or “minerBlock” extensions, and the “NoScripts” add-on for Firefox users, to stay secure.

PC users can also check if their CPU resources are being stealthily abused by malware through the Windows Task Manager or Resource Monitor functions.

Threats from cryptocurrency mining malware is rapidly growing, with the CoinHive variant becoming the sixth most-used malware in October, according to the latest Global Threat Impact Index report by Check Point Software, a cyber-security solutions provider.