Blockchain analytics firm Chainalysis has labeled October 2022 as “the biggest month in the biggest year ever for hacking activity” with the total hacked value for the month nearly reaching $718 million.

Despite not being more than halfway through the month, Chainalysis said 11 different hacks on decentralized finance (DeFi) protocols had seen hundreds of millions exploited.

Four exploits alone took place on Oct. 11 worth around $122 million. Hackers siphoned $200,000 in crypto using a smart contract from crypto wallet Rabby Wallet, $1.89 million from blockchain QANplatform’s Ethereum bridge, $2 million from TempleDAO and a $118 million exploit on the Solana-native Mango Markets.

Chainalysis says 2021 was the biggest year for blockchain-based hacks on record both in terms of total value hacked and the total number of hacks, but at the current rate, 2022 could “likely surpass” last year’s figures as over $3 billion has been exploited across 125 hacks so far.

The firm says it’s seeing a shift in where exploits are taking place too.

In 2019 most hacks took place on centralized cryptocurrency exchanges but as those companies increased security, the huge majority of hacks, around 90% in 2022, have taken place on DeFi protocols.

Related: From neglecting security to bad tokenomics, DeFi has played a hand in its own decline

The biggest target for hackers is cross-chain bridges, with three bridges targeted this month accounting for 82% of October’s losses. According to Chainalysis, the largest of these bridge hacks was a roughly $100 million exploit in the bridge between crypto exchange Binance’s BNB Smart Chain and Beacon Chain.