Tether’s Blacklisting Delay: A $78 Million Loophole for Criminals

A recently published report by blockchain compliance firm AMLBot reveals a significant flaw in Tether’s wallet blacklisting process. This delay allowed over $78 million in illicit USDT transfers to slip through before the blacklisting became effective. The investigation uncovered a critical vulnerability in Tether’s multi-signature contract setup on both Ethereum and Tron networks.

The report, released on May 15, details how Tether’s blacklisting process, involving a two-step multi-signature transaction, creates a noticeable time gap. This gap, ranging from minutes to hours depending on the blockchain, provides a window of opportunity for malicious actors to move funds before the blacklist officially takes effect. The first transaction acts as a warning, giving criminals ample time to react.

One specific example highlighted a 44-minute delay between the initial blacklisting submission and its enforcement. During this period, funds were successfully moved. AMLBot’s analysis shows that this wasn’t an isolated incident. Over $28.5 million was withdrawn during such delays on the Ethereum blockchain between November 28, 2017 and May 12, 2025. The Tron network saw an even larger amount, with approximately $49.6 million moved before blacklisting took effect. This represents a significant amount of illicit funds successfully laundered through exploiting this delay.

The report underscores the risks associated with this vulnerability, especially for those familiar with blockchain technology. The process provides a clear signal, allowing malicious actors to swiftly react and move their assets before being frozen. While Tether has previously promoted its asset freezing capabilities, this report casts doubt on the speed and effectiveness of those procedures. This delay can be seen as a critical failure in the security protocol, leading to significant financial losses and highlighting a concerning lack of real-time protection.

Key Findings:

• A significant delay in Tether’s blacklisting process allowed for the transfer of over $78 million in illicit USDT.
• This vulnerability stems from the multi-signature contract setup on Ethereum and Tron blockchains.
• Malicious actors exploit the delay by monitoring transactions and acting before blacklisting is enforced.
• The report underscores the need for improved security measures and faster processing times for efficient and timely compliance.

The implications are serious for the wider cryptocurrency ecosystem, raising questions about the security and reliability of stablecoins and the need for enhanced regulatory oversight. The future of Tether and other stablecoin providers might now be at stake as the speed and efficiency of asset freezing mechanisms are called into serious question.

Example of USDt blacklisting transactions. Source: AMLBot