TechFlow news — On April 3, according to 3155.eth, several top MEV bots were targeted in a hacking attack. The transaction modules within sandwich arbitrage operations were replaced, resulting in over $20 million in losses. This incident could become a major turning point for the entire MEV ecosystem.
According to GaoFlynn, technical advisor at TechFlow, MEV bots detect others’ intent to purchase tokens and front-run those trades by buying the same tokens at slightly lower prices—this is known as frontrunning. After the victim’s transaction executes, the bot automatically sells the tokens at a profit, completing a "sandwich" attack. Typically, a bundle consists of three transactions: 1) large buy-in, 2) the victim’s trade (sandwiched in the middle), and 3) large sell-off. In this attack, hackers obtained the original bundle data, then replayed or reconstructed it, replacing transaction #2 with their own—swapping out the bot’s funds with cheaper tokens.
