Netflix users are being warned to avoid clicking on suspicious email links after a phishing scam was uncovered that security experts say is designed to steal credit card details.

A Twitter profile linked to suspected Russian hackers, which last year pushed out stolen health documents of Olympic athletes, resurfaced on Wednesday - leaking files.

The group has been using this attack technique in campaigns since at least July 2016, ESET researchers said.

The attacks are thought to have begun after a security researcher published a proof-of-concept exploit in December.

The Meltdown and Spectre flaws affect nearly every modern processor and impact a range of devices such as computers, smartphones, tablets and servers.

"A person cannot live in those conditions for ever," Ecuador's foreign minister Maria Fernanda Espinosa said.

Although Twitter is no stranger to phishing scams, the latest incident does highlight serious flaws in Twitter's ad approval system.

Researcher Arnau Code said he has already successfully tested the CoffeeMiner attack in real-life scenarios including in cafes.

"It's not clear if we're looking at an early test of an attack, or part of a 'legitimate' mining operation," researchers said.