Twitter said hackers accessed its internal systems to hijack the accounts of some of the platform's top voices and used them to solicit digital currency.
The accounts included those of U.S. presidential candidate Joe Biden, reality TV star Kim Kardashian, former U.S. President Barack Obama and billionaire Elon Musk.
The company said employees with access to its internal systems had been successfully targeted by hackers who "used this access to take control of many highly-visible (including verified) accounts and Tweet on their behalf."
"We’re looking into what other malicious activity they may have conducted or information they may have accessed and will share more here as we have it," it said.
Twitter temporarily took the extraordinary step of preventing for several hours at least some verified accounts from publishing messages altogether.
It said it would restore access only when it was certain it could do so securely.
Publicly available blockchain records show the apparent scammers received more than $100,000 worth of cryptocurrency.
Chief Executive Jack Dorsey earlier said the company was diagnosing the problem and pledged to share "everything we can when we have a more complete understanding of exactly what happened."
Shares in the social media company tumbled almost 5 per cent in trading after the market close before paring their losses.
Other high profile accounts affected: rapper Kanye West, Amazon founder Jeff Bezos, investor Warren Buffett, Microsoft co-founder Bill Gates, and the corporate accounts for Uber and Apple.