On June 20, 2026, Ethereum's most notorious sandwich bot jaredfromsubway.eth had its treasury drained.
$7.5 million, one transaction, one block. The automated hunter, known for sandwiching others' transactions and making millions annually, fell into its own trap in its hunting grounds.
This wasn't the first time. Three years ago, a hacker disguised as a regular validator siphoned $25.2 million from the pockets of five top sandwich bots using 32 ETH as an entry ticket.
The predator became the prey. But the truly remarkable part of the story is not about who wins or loses, but how this "bot versus bot" arms race is fundamentally shaking Ethereum's transaction security.
01 Every Trade You Make Is Being Front-Run
Let's first clarify what sandwich bots are up to.
In decentralized exchanges like Uniswap, your trade intent is placed in a public waiting area called the mempool before being confirmed on-chain. Everyone can see what you intend to buy, how much, and the maximum slippage you are willing to accept.
Sandwich bots keep a constant eye on this waiting area 24/7. If it spots you trying to make a large purchase of a token, it will front-run you by placing a buy order to drive up the price, then follow up with a sell order at a higher price.
You end up "sandwiched" in the middle, paying more and receiving less of the token.
It may only cost you a few dollars per trade, an amount you might not even notice. Yet, that's the insidious part of it.
Every day, thousands of trades are sandwiched, accumulating into a substantial "invisible tax."
It's not just regular traders getting clipped; liquidity providers are in an even worse position.
AMMs' price adjustments always lag behind centralized exchanges like Binance, allowing external arbitrageurs to repeatedly extract assets from the pool at a lower price due to the delay. Academically termed "impermanent loss," some studies suggest that the value loss inflicted on LPs is orders of magnitude higher than the sum of all sandwich attacks.
In simple terms, from searcher to builder to validator, the entire MEV value chain is extracting value from ordinary users every day.
Jared is the top player in this game, at one point controlling nearly 70% of Ethereum mainnet sandwich attack traffic.
02 66 Traps and a Rugged Pull
The retaliation in 2026 played out like a sophisticated crime movie.
The hacker spent weeks deploying 66 fake token contracts, each paired with a fake liquidity pool. These pools, intricately designed, displayed on-chain highly profitable arbitrage signals, specifically enticing Jared's scanning algorithm.
Jared took the bait. Its bot automatically sandwich attacked these fake tokens, and during the interaction, a routing contract granted transfer permission to the attacker's contract (called approve).
The crucial part came next. To save on gas fees, Jared's developer did not include the logic to revoke the approval after the transaction. In the world of smart contracts, once permission is given, unless approve is actively zeroed out, it remains valid indefinitely. This is known as "infinite approval."
With all 66 traps in place, the hacker made a single transaction in the same block, calling transferFrom, and directly transferred all of Jared's 1474.58 WETH, 2.87 million USDC, and 2.09 million USDT from the treasury. The funds were swiftly exchanged on-chain for thousands of ETH and sent to Tornado Cash.
Then, gone.
The April 2023 incident was even more aggressive, with the attack directly targeting the trust backbone of the Ethereum PBS architecture.
The hacker staked 32 ETH to become a validator, then initiated a massive slippage transaction in an extremely illiquid Uniswap V2 pool (containing only 0.005 WETH and 4.5 STG), intentionally creating an attractive sandwich attack opportunity.
The bots took the bait. To execute this arbitrage, they plunged in with 2454 WETH (about $4.4 million), just to swap for that measly 4.5 STG, hoping to sell back for a profit of less than 0.35 ETH. The ratio of transaction amount to profit was as high as 7000:1.
Then came the final blow. When it was this malicious validator's turn to package the block, it sent a deliberately crafted invalid block header to the Flashbots relay. The relay code had a fatal error-handling vulnerability: as long as the signature verification passed, even if the block header was invalid, it would prematurely return the plaintext transaction content of the sandwich bot to the validator.
Upon receiving the plaintext, the validator discarded the invalid block and reassembled a new one: it placed the sandwich bot's 2454 WETH buy order at the front, followed by inserting its own attack contract to drain all the WETH in the pool using 158 STG.
And it wasn't just WETH. The hacker manipulated multiple token pools including AAVE, SHIB, CRV, UNI, MKR, totaling over $25 million through the same method. This included 7461 WETH and $5.3 million USDC.
A 32 ETH ticket resulted in nearly an eight hundred-fold return.
03 Everyone's Wallet Has the Same Vulnerability
While these two incidents may seem like a battle in the bot world, the issues they exposed directly affect every ordinary user.
The exploit that Jared fell victim to may also exist in your wallet. Many people habitually click "Approve unlimited transfer allowance" when using Uniswap or claiming airdrops. Once the relevant contract is breached, hackers can empty your stablecoins using the same transferFrom method.
A deeper threat lies in MEV making Ethereum insecure.
When the arbitrage profit in a block far exceeds the block reward, validators have an incentive to cheat: by ignoring a newly released block by others, they instead reorganize a chain at a historical block height, taking ownership of high-profit transactions. If this kind of "time bandit attack" occurs frequently, Ethereum's transaction finality will collapse.
MEV bots' high-frequency frontrunning and Gas Auction (PGA) also instantaneously consume a large amount of block space, driving up the network-wide gas fees. Even if you're just making a simple transfer, you still have to foot the bill for the game between bots.
Block construction is also rapidly centralizing. The capture of high MEV heavily relies on highly precise algorithms and large-scale infrastructure, with a few professional builders controlling the vast majority of block packaging share. Once they collude, Ethereum's censorship resistance becomes nothing but a mere promise.
The Ethereum community has taken two different paths in response to the sandwich attack. At the protocol level, ePBS aims to incorporate the relayer's function into the consensus layer to eliminate third-party vulnerabilities at the protocol level. On the other hand, encryption-based memory pools (such as the Shutter Network) utilize time-lock encryption technology to keep transactions in a ciphertext state until the ordering is completed, effectively preventing a sandwich attack from obtaining input data.
However, these solutions are still a ways off from full implementation. Currently, the most practical self-rescue options include two key actions.
First, switch your wallet's RPC to either Flashbots Protect or MEV Blocker. By bypassing the public mempool, transactions are not only protected from sandwich attacks but can also reclaim a portion of arbitrage profits through Order Flow Auctions (OFA), with only a slight delay of one or two blocks on average.
Second, regularly inspect and revoke unnecessary token allowances in your wallet. Many users casually approved unlimited spending at a DEX six months ago and have since forgotten about it, leaving that approval lingering on the chain. Use tools like Revoke.cash to scan and revoke these approvals, a task that only takes a few minutes.
Jared's $7.5 million tuition fee was a costly lesson but at least served as a valuable learning experience.
In the dark forest, even hunters can become the hunted. Yet, the first to shed blood will always be the unguarded.
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