Yet another cryptocurrency firm has been hacked to the tune of millions of dollars.

Meter provides decentralized finance (DeFi) infrastructure services, linking siloed blockchains for users with so-called “cross-chain bridges.”

Over the weekend, it revealed that an unauthorized intruder had managed to exploit a bridge vulnerability to mint a large number of Binance Coins (BNB) and wrapped Ethereum (WETH), while running down its reserves.

After halting bridge transactions immediately, the firm investigated the source of the bug.

“The extended code had a wrong trust assumption which allowed hacker to call the underlying ERC20 deposit function to fake an BNB or ETH transfer,” it explained on Twitter.

“The only impacted tokens were native gas tokens (WETH and BNB), and only Meter and Moonriver networks were impacted.”

Meter admitted it lost $4.4m in the raid but said it would compensate those affected while working with the authorities to trace its attacker.

“We urge all the liquidity providers that provide liquidity involving WETH and BNB to remove liquidity from the pool and wait for an additional announcement from the Meter team,” it added. “Please try avoid trading in these pairs as well.”

Meter urged the hacker to return the funds but has not publicly offered its assailant a bug bounty reward for their safe return, as did two other crypto firms compromised last week.

DeFi provider Quibit Finance proffered a reward of $2m to its attackers and a promise not to press charges after they made off with $80m.

Then a few days later, another cross-chain bridge provider, Wormhole, lost an estimated $322m after attackers stole 120,000 ETH. This time it offered a staggering $10m to the hacker.

A few days later, proprietary trading firm Jump Trading said it replenished those funds “to make community members whole and support Wormhole now as it continues to develop.”