Retool, a software development company, disclosed that 27 of its cloud customers fell victim to a targeted SMS-based social engineering attack. This incident, which occurred on August 27, 2023, was exacerbated by a Google Account cloud synchronization feature introduced in April 2023, which Retool referred to as a “dark pattern.”
Furthermore, the attack began with an SMS phishing attempt targeting Retool employees, where the threat actors impersonated IT team members and tricked an employee into clicking a seemingly legitimate link to address a payroll-related issue. This employee’s compromise allowed the attackers to gain access to internal admin systems, ultimately leading to the takeover of 27 customer accounts in the cryptocurrency industry. One affected customer, Fortress Trust, reportedly lost close to $15 million worth of cryptocurrency in the attack.
The attackers’ modus operandi included deepfaking the “actual voice” of an IT team member to obtain multi-factor authentication (MFA) codes, enabling them to add their device to the employee’s Okta account and gain control over Google accounts.
This control over Google accounts, combined with access to Google Authenticator’s cloud-synced one-time codes, granted the attackers elevated access to internal systems. The incident underscores the risks of syncing one-time codes to the cloud and emphasizes the importance of relying on FIDO2-compliant hardware security keys or passkeys to thwart phishing attacks.
While the identity of the hackers remains undisclosed, their tactics share similarities with a financially motivated threat actor known as Scattered Spider (aka UNC3944), which is recognized for its advanced phishing techniques.
The attack also highlights the increasing use of deepfakes and synthetic media in cyber threats, prompting a U.S. government advisory warning about their potential for malicious purposes, including business email compromise (BEC) attacks and cryptocurrency scams.