Thousands of websites run by UK and US government agencies were infected for several hours yesterday with code that allows web browsers to secretly mine digital currencies, technology news site The Register reported.
Over 4,200 sites were infected with a malicious version of a widely used tool, Browsealoud from UK software maker Texthelp, which reads out webpages for people with vision problems, according to The Register.
The news comes in the backdrop of increasing number of cyber -attacks using software that forces infected computers to mine crypto currencies on behalf of hackers.
Attacks of the type have increased in recent months with a steep increase in the volume of trading in bitcoin and other crypto currencies.
According to the Register, the tainted version of Browsealoud caused inserted software for mining the digital currency Monero to run on computers that visited infected sites, generating money for the hackers behind the attack, The Register said.
Meanwhile, the UK Information Commissioner's Office (ICO) took down its website after a warning that hackers were taking control of visitors' computers to mine cryptocurrency.
''This type of attack isn't new – but this is the biggest I've seen. A single company being hacked has meant thousands of sites impacted across the UK, Ireland and the United States,'' IT security consultant Scott Helme told Sky News.
''Someone just messaged me to say their local government website in Australia is using the software as well.''
A spokesperson for the National Cyber Security Centre said, ''NCSC technical experts are examining data involving incidents of malware being used to illegally mine cryptocurrency.
''The affected services have been taken offline, largely mitigating the issue. Government websites will continue to operate securely. At this stage there is nothing to suggest that members of the public are at risk.''