![A circle overlaid with ][ symbols, followed by "Ostium" in orange capitals](https://primary-cdn.web3isgoinggreat.com/entryImages/logos/resized/ostium_300.webp)
The attacker siphoned at least $24 million USDC from the protocol, which they quickly swapped into ETH and laundered via Tornado Cash.
Ostium loses at least $24 million to oracle exploit
Decentralized perpetual futures exchange Ostium was drained of at least $24 million after an attacker manipulated its oracle system — a system that pulls in off-chain price data. After the attacker apparently gained access to the private key used to sign oracle messages, they were able to submit future-dated oracle reports that tricked the system into thinking trades were profitable.
Polymarket customers lose $2.97 million, company blames third-party vendor
Polymarket customers have lost around $2.97 million to an attacker who then swapped stolen Polymarket USD (pUSD) to ETH.
Polymarket, a crypto-based prediction markets platform, quickly made an announcement to claim that a third-party vendor had been compromised to allow an attacker to inject a malicious script into the website frontend. Polymarket has said it will refund affected customers.
Users of the SecondFi Cardano wallet lose $2.4 million in series of hacks
Users of the Cardano wallet SecondFi (formerly Yoroi) have lost a cumulative 16 million ADA (~$2.4 million) across three attacks targeting a vulnerability in the project's wallet generation code.
After the attacks commenced, SecondFi "rescued" another 129 million ADA (~$19.4 million) by moving the assets to a third party entity. They have announced that an external accounting firm will verify the funds and process user claims.
Taiko bridge exploited
The Taiko bridge, which allows assets to be transferred between the Ethereum mainnet and the Taiko Ethereum layer-2 chain, was exploited for at least $1.7 million before the network was halted, limiting losses. An attacker was able to forge withdrawal requests to appear as though they matched real deposits. Crypto security firm BlockSec said that the attacker may have gained access to a signing key that had been exposed on GitHub.
Highly active MEV bot known as jaredfromsubway.eth drained for $7.7 million
On blockchains like Ethereum, a strategy known as "MEV" (short for "maximal extractable value") allows intermediaries to profit from manipulating the structure of blocks added to the chain — often reordering or "sandwiching" transactions in ways that extract profits. Automated software known as MEV bots make a business out of this strategy, and one of the most active is a bot called jaredfromsubway.eth — likely so named after one-time Subway spokesman and convicted sex offender Jared Fogle because of its strategy of "sandwiching" transactions by placing trades on both sides, causing the original trader to pay more.
On June 20, an attacker used a series of contracts to cause the bot to grant token approvals that were later used to drain 4,427 ETH ($7.7 million). Some of the funds were then laundered through Tornado Cash.
Aztec Connect hacked for a second time in less than a week
Three days after Aztec Labs' deprecated Aztec Connect blockchain bridge was exploited for $2.1 million, the project has been hacked again for the same amount. Aztec Labs confirmed the second exploit, again trying to emphasize that the code was deprecated four years ago.
The hacks are part of a spate of exploits targeting legacy smart contracts belonging to projects including Raydium and DxSale. Although some projects have developed techniques to circumvent the immutable nature of blockchains and allow smart contracts to be upgraded or retired, many legacy contracts cannot be changed or shut down, leaving them vulnerable to attack indefinitely.
Deprecated project Aztec Connect exploited for $2.1 million
Aztec Connect, an abandoned defi privacy bridge from Aztec Labs, was drained of $2.1 million after an attacker exploited a bug in the project's smart contracts. Although the project was deprecated three years ago, funds remained in the legacy system. "Aztec Labs holds no admin keys or control over the system; it cannot be paused or upgraded by us," the project posted on social media.
The theft is only the latest in a string of attacks targeting vulnerable legacy smart contracts, many of which cannot be deleted, paused, or changed due to blockchains' immutable nature. Raydium and DxSale are two other platforms that have recently suffered losses due to old, insecure code.
Secret bridge exploited for $4.67 million a week before anyone notices
The bridge between the Cosmos-based Secret network and Axelar network was exploited via an infinite mint bug that went unnoticed for a week. An attacker exploited a smart contract in order to mint a large quantity of wrapped Axelar tokens on the Secret network, which they then redeeemed for around $4.67 million.
The exploit, which occurred on June 10, went unnoticed until June 17, when a transaction failed with a message suggesting that more tokens had been bridged out of the Secret network than had been bridged in.
Secret has warned, "If you hold Axelar-bridged saXXX tokens on Secret, please be aware their backing was affected and your funds may be lost."
Raydium users lose $1.34 million after legacy smart contract exploited
An attacker exploited a legacy smart contract that had been used by the Raydium Solana DEX before it was deprecated in 2021. Though the contract was unused, there were still funds in the liquidity pools affected by the vulnerable contract. Using fake LP tokens, the exploiter was able to trick an old smart contract with insufficient validation into allowing them to withdraw assets.
Raydium has said it will compensate users who lost funds in the exploit.
Humanity Protocol loses $36 million to employee laptop compromise
Humanity Protocol, a decentralized identity project that uses palm scans to try to prove that users are human, has suffered a $36 million loss after attackers compromised a laptop belonging to an employee. After the laptop was infected with malware, the malicious code gained root access, then stole seven private keys that were reportedly accidentally stored in a backup. Several of the keys were sufficient to satisfy multisignature requirements, which are intended to prevent private key leaks from allowing attackers to gain control over sensitive infrastructure like bridges. With multisignature wallets, keys are supposed to be stored separately across multiple individuals and devices; however, in this case, attackers only needed to compromise one laptop to gain control over multisig-protected contracts.
With the keys, the attacker stole more than 6 million of Humanity's H token, then used other keys to upgrade a bridge and drain 141 million more tokens. With the bridge access, they also minted 300 million new H tokens. The attacker then quickly swapped the ill-gotten tokens for ETH, causing the H price to plummet by 80–90%.
Humanity Protocol markets itself as a competitor to Sam Altman's World (formerly Worldcoin), a decentralized identity project that aims to use iris scans to prove that users are unique humans. Humanity raised $20 million in 2025 from Pantera Capital and Jump Crypto.