Tether Freezes USDT Tied to Mercado Bitcoin Breach
Tether has blocked over 4.5 million USDT linked to a security incident at Brazilian exchange Mercado Bitcoin, where an attacker's wallets hold about $46 million.
Another centralized exchange has been breached, this time in Brazil, and a stablecoin issuer is already working to limit the damage. Tether froze more than 4.5 million USDT tied to the attack on Mercado Bitcoin, yet the attacker's wallets still hold far more.
A run of exchange attacks
Mercado Bitcoin is the latest in a string of hits on large trading platforms. On Oct. 29, hackers stole a record $6.3 billion from Binance. That was less than four days before the Brazilian case.
Before Binance came Bitget. On Sept. 24, attackers drained $388 million from its wallet infrastructure, and the exchange covered the losses from its protection fund.
Earlier cases fit the same pattern. Phemex lost $69 million from a hot wallet in January 2025. In February, Bybit lost about $1.5 billion after hackers manipulated the approval process for one of its Ethereum cold wallets. The FBI blamed North Korean hackers, the TraderTraitor operation, for the Bybit and Binance thefts. Investigators have found no link between those operations and the Mercado Bitcoin breach.
What Mercado Bitcoin says happened
The exchange reported that it detected the incident overnight in one of its systems and contained it. It suspended deposits and withdrawals while the team examined suspicious asset movements.
The company insists customers lost no money and no personal data leaked. It has not put a figure on the attack and has not said whether corporate reserves were affected.
A restoration update gave no reopening timetable, and the status page showed a partial outage.
Mercado Bitcoin also posted suspicious destination addresses on Bitcoin, Ethereum-compatible networks, Solana, Stellar and Tron. The aim is to help trace the funds and possibly recover them.
Tether steps in
When a stablecoin issuer freezes tokens, those coins can no longer be moved by whoever holds them. Tether CEO Paolo Ardoino confirmed on Nov. 2 that it had done this for more than 4.5 million USDT connected to the incident.
Tether has a stake here beyond its role as issuer. It announced a $20 million strategic investment in Mercado Bitcoin in July, meant to support the exchange's push into tokenization, payments and other digital financial services.
The freeze is not the only one. On-chain analyst Specter said security researchers and stablecoin issuers working together had immobilized more than $9 million across nine digital assets, including USDC, PAXG and RLUSD.
What the attacker still holds
Arkham Intelligence, a blockchain analytics firm, identified roughly $46 million in wallets attributed to the attacker. That total includes $8.37 million in Ethereum, $8.24 million in Bitcoin and $1.76 million in PEPE.
Our View
The frozen sum is small next to the roughly $46 million that Arkham Intelligence attributes to the attacker's wallets. Whether more of it can be blocked depends on which issuers and projects can act on the published addresses. Until the exchange gives a reopening date, how far its systems were affected stays unclear.
Source: CryptoSlate