Israel Sends Nomad Exploit Suspect to US
Israel has extradited Alexander Block, an Israeli-Russian citizen accused of taking about $2.8 million in digital assets from the Nomad crypto bridge, to the United States. The transfer followed the rejection of his final appeal by Israel’s Supreme Court, according to Bitcoin.com News.
The case centers on an alleged August 2022 exploitation of a Nomad smart-contract vulnerability that prosecutors say was later used by others to drain more than $186 million from a wallet controlled by the bridge.
What happened
Israel handed Block to U.S. authorities early Thursday, according to Unchained, which said the State Attorney’s Office announced the extradition. Block was previously known as Alexander Gurevich until 2025, Unchained reported. Calcalistech spells his surname as Blok, while Bitcoin.com News, Decrypt and Unchained use Block.
The U.S. case concerns the Nomad bridge incident in August 2022. Decrypt reported that prosecutors allege Block exploited a flaw in the bridge and took about $2.8 million. The same alleged exploit exposed a weakness that other users subsequently used to withdraw more than $186 million from a Nomad-controlled wallet.
Calcalistech reported that prosecutors allege Block modified computer code used to verify whether assets had been locked. That modification allegedly caused the system to issue digital tokens without the required underlying collateral. After determining that the system did not identify the alteration, he allegedly withdrew tokens worth approximately $2.8 million from a Nomad-controlled wallet on August 1, 2022.
Unchained reported that prosecutors allege Block first made six test transfers and then conducted four withdrawals worth more than $2.8 million around August 1, 2022. It also reported allegations that he spread tokens across several addresses and swapped them in an effort to conceal their origin.
An eight-count federal indictment was filed against Block in the Northern District of California on August 16, 2023, according to Unchained. The reported charges include three counts of money laundering, four counts of computer fraud and one count of transporting stolen property.
Why it matters
The extradition places the alleged Nomad exploit before a U.S. court after a cross-border legal process involving Israeli authorities, the Israeli Supreme Court and a U.S. extradition request. Bitcoin.com News reported that Israel’s Supreme Court rejected Block’s final appeals before the handover.
The Israeli court’s treatment of the alleged conduct is also significant for disputes over whether activity executed through a smart contract can be unlawful when the software technically allows it. Decrypt reported that the Supreme Court found that exploiting a programming flaw can amount to unlawful computer intrusion even if the software permitted the relevant action.
That conclusion addresses a recurring legal question around decentralized applications. A transaction may be recorded publicly and processed automatically, but the court’s reported ruling indicates that those features do not by themselves resolve whether the use of a vulnerability was authorized.
Money-laundering allegations are another important part of the case. Unchained reported that the indictment includes three such counts, while the reported allegations include moving tokens across several addresses and swapping them. The allegations have not been adjudicated in the U.S. proceedings described by the reports.
Background and context
Nomad is a cross-chain bridge, a system designed to lock assets on one network and issue matching tokens on another. According to the prosecution account described by Decrypt, a June 2022 software update left a flaw in Nomad’s smart contracts.
Prosecutors say the update allowed withdrawals to route through a process called process() rather than proveAndProcess(), bypassing the check intended to confirm that assets had been locked before corresponding tokens were issued. Calcalistech reported that the alleged code alteration in Block’s case enabled tokens to be issued without the required collateral.
Decrypt reported that Block argued that using contracts as written should not be treated as a crime. Israel’s Supreme Court rejected that argument, according to the outlet, holding that exploitation of a smart-contract flaw can constitute unlawful intrusion into a computer system.
The ruling also addressed the public nature of blockchain records. Decrypt reported that the court found publicly visible blockchain activity does not preclude a money-laundering charge because wallet addresses do not identify the people who control them. Calcalistech similarly reported that the court viewed intrusion into computer material as including exploitation of security vulnerabilities and programming errors.
Unchained reported that Block was arrested in May 2025 at Ben-Gurion Airport while preparing to board a flight to Russia. The outlet said he had recently changed his surname and obtained a passport under the new name.
What to watch
The next central question is how the U.S. case proceeds after the extradition, including the handling of the reported computer fraud, money laundering and stolen-property counts. The reports do not state a trial date or detail any response from Block in the U.S. proceedings.
It will also be important to follow how U.S. prosecutors present the alleged technical sequence, including the reported test transfers, withdrawals and subsequent token movements. The indictment and the allegations outlined by prosecutors will need to be tested through the U.S. legal process.
The Israeli Supreme Court’s reported reasoning may also remain relevant in future cases involving smart-contract vulnerabilities. Its conclusion, as described by Decrypt and Calcalistech, distinguishes between software behavior that is technically possible and conduct that courts may regard as authorized or lawful.
