Crypto exchange hacked again: possibly $40 million stolen

The crypto sector has been shaken up again by a major cyber attack. Mercado Bitcoin, Brazil's largest crypto exchange, temporarily halted deposits and withdrawals on Monday following a security incident.

According to security researchers, more than $40 million worth of suspicious transactions have been discovered. The attack comes just days after Binance's historic billion-dollar hack.

Mercado Bitcoin confirmed Monday, November 2, that a security incident occurred within one of its systems. The company says it quickly spotted the attack and got it under control.

According to blockchain security firm Hypernative, more than $40 million worth of suspicious transactions were discovered from wallets linked to Mercado Bitcoin.

The crypto coins were moved across about ten different blockchains. These include Bitcoin (BTC), Ethereum (ETH), Solana (SOL) and various other digital coins.

How the attacker gained access is not yet clear. The transactions are similar to ordinary transfers approved from the affected wallets. Investigators are trying to determine how the attacker was able to obtain that permission.

Mercado Bitcoin has not yet confirmed the amount of 40 million dollars itself. The crypto exchange also emphasizes that, according to the company, customers have not lost any money and that no customer data has been leaked.

As a precaution, deposits and withdrawals have been temporarily suspended. As a result, users cannot currently transfer crypto coins to the trading platform or withdraw their assets.

The company is investigating the attack and trying to track the moved crypto coins. Mercado Bitcoin also cooperates with the competent authorities.

It is not yet known when deposits and withdrawals will resume.

The attack in Brazil comes at a time when the security of crypto exchanges is already under discussion.

Last Thursday, Binance was hit by the biggest crypto theft ever. Hackers then managed to loot about 6.3 billion dollars worth of crypto coins.

The attack caused great unrest among customers. Binance temporarily halted withdrawals and then saw billions of dollars flow away when users were able to withdraw their crypto coins again.

A month earlier, crypto exchange Bitget was also hit by a major attack. The damage was estimated at hundreds of millions of dollars.

In addition, this year there were major security incidents at Liquid Network, Kelp Dao and Drift Protocol, among others.

According to previous reports, Liquid Network was about 320 million dollars, a large part of which was later returned. At Kelp Dao and Drift Protocol, amounts of approximately 292 million and 285 million dollars respectively were mentioned.

The series of attacks shows that not only major crypto exchanges are targeted. Platforms on which users lend, trade or move crypto coins between blockchains can also be vulnerable.

According to figures shared by The Kobeissi Letter, the crypto sector would have experienced around 750 security incidents by 2026, with a total estimated loss of around $9 billion.

That would mean an increase of 133 percent compared to the whole of 2025.

However, those figures have not been independently confirmed. Other security researchers use different definitions for cyber incidents and therefore arrive at different numbers.

In any case, the attack on Binance is responsible for a large part of the damage reported this year.

Not every crypto hack proceeds in the same way. Sometimes attackers gain access to the wallets of a trading platform. In other cases, they misuse errors in software or mislead employees to circumvent security measures.

At Mercado Bitcoin, it has not yet been determined which method has been used.

The Brazilian crypto exchange has promised to keep customers informed of the investigation. It is especially important for users when they can withdraw their crypto coins again and whether the suspicious transactions have actually led to financial damage for the company.