Cyber security experts are warning that consumers can also be targeted by .
A new variant of known malware Petya is believed to be behind the chaos, which initially hit Ukraine, before spreading to companies in a number of other countries, including the UK.
However, it’s not just big businesses that are under threat.
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“Consumers are also at risk and should be wary if they are running operating systems that are vulnerable to the exploit, in other words if you have not patched,” Raj Samani, chief scientist & fellow at McAfee, told the Independent.
Like WannaCry, which crippled the NHS in May, the Petya-based malware is believed to be making use of the EternalBlue exploit that was stolen from the National Security Agency.
Though Microsoft patched the issue, which took advantage of a flaw in Windows, users who haven’t downloaded the fix are vulnerable.
The ransomware is encrypting users’ files and cutting off access to them, and demanding payment of $300 in Bitcoin.
“Who is being targeted and why? The short answer is everyone – individuals and organisations alike,” said Peter Groucutt, the managing director of Databarracks.
However, he did add that, “larger organisations with valuable datasets and a public reputation to protect obviously represent high-value targets, and often attract the most sophisticated attacks as a result.”
The attack is believed to spreading through spear phishing emails, where unsuspecting targets click on a malicious link.
“Though this attack is largely targeting companies, it’s important consumers also stay vigilant and take precautionary measures,” said Gary Davis, McAfee’s chief consumer security evangelist.
The company is advising computer users to check the content of emails for legitimacy, by hovering over a link to see if it leads to a reliable URL, for instance, or searching for anything suspicious-looking before clicking it.
Users should also ensure their antivirus is up-to-date, and back up their computer’s files.