July 15 (UPI) -- Twitter on Wednesday said it identified a coordinated attack on employees that led to the accounts of several high profile people including Barack Obama, Joe Biden, Jeff Bezos, Bill Gates and Elon Musk tweeting out a cryptocurrency scam.
Twitter Support tweeted that the posts soliciting cryptocurrency payments were part of a "coordinated social engineering attack" that successfully targeted Twitter employees with access to internal systems and tools.
"We know they used this access to take control of many highly-visible (including verified) accounts and tweet on their behalf," Twitter said. "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."
Twitter said that it immediately locked down the affected accounts and removed the tweets posted by the attackers while taking further action to prevent other verified accounts that had not shown evidence of being compromised from tweeting or changing their passwords briefly Wednesday evening.
The company said the compromised accounts remain locked and will be returned to the original owners "only when we are certain we can do so securely."
The affected accounts, which also included rapper Kanye West, investor Warren Buffet and Apple's official account, all sent out messages including the same bitcoin account promising to double any amount sent to it.
"Everyone is asking me to give back, and now is the time," one form of the tweet read. "You send $1,000, I send you back $2,000."
Biden's campaign said Twitter locked the Democratic presidential candidate's account and immediately removed the related tweet.
"We remain in touch with Twitter on the matter," his campaign said.
A representative for Gates also confirmed to The Verge that the Microsoft co-founder did not send the tweet.
"This appears to be part of a larger issue that Twitter is facing. Twitter is aware and working to restore the account," the representative said.
The tweets began at about 3 p.m. and the bitcoin account associated with the messages has received about $100,000.