Hackers have stolen $1.4 billion this year using crypto bridges

Crypto investors have been hit hard this year by hacks and scams. One reason is that cybercriminals have found a particularly useful avenue to reach them: bridges.

Blockchain bridges, which tenuously connect networks to enable the fast swaps of tokens, are gaining popularity as a way for crypto users to transact. But in using them, crypto enthusiasts are bypassing a centralized exchange and using a system that’s largely unprotected.

A total of around $1.4 billion has been lost to breaches on these cross-chain bridges since the start of the year, according to figures from blockchain analytics firm Chainalysis. The biggest single event was the record $615 million haul snatched from Ronin, a bridge supporting the popular nonfungible token game Axie Infinity, which lets users earn money as they play.

There was also the $320 million stolen from Wormhole, a crypto bridge backed by Wall Street high-frequency trading firm Jump Trading. In June, Harmony’s Horizon bridge suffered a $100 million attack. And last week, almost $200 million was seized by hackers in a breach targeting Nomad.

“Blockchain bridges have become the low-hanging fruit for cyber-criminals, with billions of dollars worth of crypto assets locked within them,” said Tom Robinson, co-founder and chief scientist at blockchain analytics firm Elliptic, in an interview. “These bridges have been breached by hackers in a variety of ways, suggesting that their level of security has not kept pace with the value of assets that they hold.”

The bridge exploits are occurring at a striking rate, considering it’s such a new phenomenon. According to Chainalysis data, the amount stolen in bridge heists accounts for 69% of funds stolen in crypto-related hacks so far in 2022.

When swapping a token from one chain onto another — as in sending some ether from ethereum to the solana network — an investor deposits the tokens into a smart contract, a piece of code on the blockchain that enables agreements to execute automatically without human intervention.

That crypto then gets “minted” on a new blockchain in the form of a so-called wrapped token, which represents a claim on the original ether coins. The token can then be traded on a new network. That can be useful for investors using ethereum, which has become notorious for…