A mobile spearphishing attack targeting “a small number of employees” is what led to the unprecedented, major attack earlier in the month on high-profile Twitter accounts to push out a Bitcoin scam.
The company posted an update late Thursday on the situation, which has been unfolding since July 15, when 130 accounts of high-profile users such as Bill Gates, Elon Musk, Apple and Uber each were hijacked at the same time to promote a bogus advance-fee cryptocurrency deal.
“This attack relied on a significant and concerted attempt to mislead certain employees, and exploit human vulnerabilities, to gain access to our internal systems,” the company said in its update. “This was a striking reminder of how important each person on our team is in protecting our service.”
On the day of the attack, Twitter revealed that the accounts fell victim to a compromise of the company’s internal systems by a group of unidentified hackers that managed to access Twitter company tools and secure employee privileges. Until Thursday, Twitter had not yet confirmed exactly how attackers got access to those internal tools, a point that the company has now clarified.
The attack required threat actors to obtain access to both Twitter’s internal network via specific employee credentials, the company said Thursday.
Since not all of the employees that were initially targeted had permissions to use the account management tools key to the attack, the attackers used a two-step approach to hack their way in, according to Twitter. First they used the initial credentials they phished to access some of Twitter’s internal systems and learn information about company processes, according to the post.
“This knowledge then enabled them to target additional employees who did have access to our account-support tools,” the company said. “Using the credentials of employees with access to these tools, the attackers targeted 130 Twitter accounts, ultimately tweeting from 45, accessing the [direct messages (DM)] inbox of 36, and downloading the Twitter Data of seven.”
An elected official in the Netherlands was one of those whose DMs (direct messages) were leaked; however, attackers did not access data for any of the former U.S. elected officials whose accounts were breached, the company said.
Once it was aware of the attack, Twitter immediately locked down thousands of verified accounts belonging to elite Twitter users and high-profile companies to try to prevent hackers from perpetrating the scam. The attack involved sending tweets from each of the hijacked accounts to promote a bogus Bitcoin deal, which promised to double the value of Bitcoin currency sent to one specific wallet.
Twitter acknowledged Thursday that there has been “concern following this incident around our tools and levels of employee access,” and said that it’s taking steps and updating its account tools to make them more “sophisticated” to prevent such a breach in the future.
Those steps include significantly limiting access to internal tools and systems to ensure ongoing account security while the company completes its investigation. This unfortunately will result in some disruption of user account service, including limiting access to the Twitter Data download feature and other processes, Twitter acknowledged.
“We will be slower to respond to account support needs, reported tweets and applications to our developer platform,” the company said in the update. “We’re sorry for any delays this causes, but we believe it’s a necessary precaution as we make durable changes to our processes and tooling as a result of this incident.”
The company continues to investigate the attack and work with “appropriate authorities” to identify and those responsible. In the meantime, there continues to be widespread speculation and reported evidence about who may be behind the hack, but no solid conclusions.
Some of the strongest evidence about the potential perpetrators was published in a number of reports pointing to the sale of Twitter account access by hackers obsessed with so-called “OG handles,” which are short-character profile names that confer a measure of status and wealth in certain online communities.
Another plausible theory also emerged around screenshots of Twitter’s internal tools that appeared on underground forums ahead of the attacks due to a bribe of a lone rogue Twitter employee, but Twitter later refuted this claim.
The FBI is said to be taking the lead in the investigation due to the massive privacy, legislative and business ramifications of the incident.
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