GOOGLE-OWNED YouTube says it has blocked a number of malicious adverts that allowed cybercrooks to syphon viewers' CPU power for mining Monero cryptocurrency.
The issue first became apparent last week, after users complained that YouTube ads were raising red flags in anti-virus software and slowing down their PC.
Security outfit Trend Micro later confirmed the malicious ad threat after detecting an almost 285 per cent increase in the number of Coinhive miners on 24 January.
It claims that the malware-ridden ads hijacked a viewer's CPU and using its power to mine the Monero cryptocurrency, adding that the mining scripts used for this 'crytpojacking' attempt were capable of mining 80 per cent of a computer's CPU power.
"Attackers abused Google's DoubleClick, which develops and provides internet ad serving services, for traffic distribution," Trend Micro said. "Data from the Trend Micro Smart Protection Network shows affected countries include Japan, France, Taiwan, Italy, and Spain."
"We speculate that the attackers' use of these advertisements on legitimate websites is a ploy to target a larger number of users, in comparison to only that of compromised devices."
Trend Micro said it quickly disclosed its findings to Google, which claims to have removed the dodgy adverts within two hours. However, reports show that the ads ran for as long as a week
"Mining cryptocurrency through ads is a relatively new form of abuse that violates our policies and one that we've been monitoring actively," a Google spokesman said.
"We enforce our policies through a multi-layered detection system across our platforms which we update as new threats emerge. In this case, the ads were blocked in less than two hours and the malicious actors were quickly removed from our platforms." µ
Bad for shareholders, mildly good for the planet
YouTube on the Tube
Claims that it hasn't ever actually worked