Twitter hack: Exchange 'blocked 1,000 Bitcoin transactions'

Elon Musk, Kim Kardashian and Barack Obama are among victims of the hack

Crypto-currency exchange Coinbase prevented thousands of pounds worth of bitcoin being transferred to scammers during the Twitter hack, it has said.

The attack saw high-profile accounts such as Bill Gates and Joe Biden falsely tweet requests for bitcoin.

Coinbase said it had blacklisted the hacker's wallet address, preventing more than 1,000 customers from sending about $280,000 (£220,000).

Twitter is still investigating the matter.

So far the company has said that the hackers targeted employees who had access to internal systems and tools.

It has now limited access to these tools and temporarily blocked users from being able to tweet bitcoin wallet addresses.

The attackers had access to 130 accounts and used 45 of these to ask members of the public to send bitcoin.

Before Coinbase noticed the scam, 14 of its users had sent about $3,000 worth of bitcoin, it told Forbes magazine.

It added it had blocked transactions "within a couple of minutes of the initial wave of scam posts".

It is believed that scammers stole about $120,000 in bitcoin in total.

"Even with this added $280,000 to the pot, this is still a very unsuccessful scam given the reach that the hackers achieved through the hacking of these highly prominent Twitter accounts," commented Dr Alexi Drew, a cybersecurity expert at King's College, London.

The move from Coinbase indicates that exchanges are attempting to stop scammers in their tracks, she said.

"Exchanges, as they seek greater legitimacy and recognition in financial markets and institutions, are taking on more of the responsibilities of that.

"While Coinbase might have these proactive policies in place, that doesn't mean that all exchanges do, nor that all crypto-currencies are in the process of being brought into the fold of regulated financial systems.

"There are other exchanges and crypto-currencies that are far more lax and far better suited to nefarious use."

Coinbase is the largest US bitcoin exchange, with 35 million users around the world.