SingularityNET: The $16.77M Bridge Hack That Paid the Thief $2.29M

At 20:21 UTC on Saturday 19 September 2026, a single transaction emptied a vault on the Ethereum blockchain of 8.72 million FET tokens, worth about $1.56 million. Two minutes and 24 seconds later the thief had swapped every one of them for 522.78 ETH, Ethereum's own currency. Nobody broke the vault open. It opened because someone showed it a valid signature.

The vault belonged to a bridge run by SingularityNET, the AI and blockchain company led by Ben Goertzel. Over the next nine hours the same attacker used that bridge, and a second permission kept in the same company's systems, to print roughly 2.3 billion new tokens out of nothing across four more coins: SingularityNET's own legacy token AGIX, NuNet's NTX, World Mobile's WMTX and Cogito's CGV. Then, at 13:10 UTC on 20 September, a SingularityNET payout contract sent its entire balance of 289,575 USDC, a digital dollar, to a wallet the attacker controlled.

On the morning of 20 September the blockchain security firm PeckShield valued what the attacker held at $16.77 million. Most headlines used that number. It was mostly paper. A transaction-by-transaction reconstruction published by Rekt News on 25 September found that the attacker turned about $2.29 million into money that could actually be spent. Bitquery, a blockchain data company that traced the attack for the Artificial Superintelligence Alliance (ASI Alliance), put the cashed-out figure at $2.25 million. The rest was freshly printed tokens that no market was deep enough to buy.

What a bridge is

Every blockchain keeps its own ledger, rather like two stock exchanges with separate share registers that cannot read each other. Ethereum cannot see Cardano. A bridge is the currency exchange booth between them. A holder hands tokens in on one side, the booth destroys (or "burns") them there, and it issues (or "mints") the same number on the other side. The new tokens are only worth something because the old ones are gone, in the same way a booth should only hand out pounds after it has taken in the dollars.

SingularityNET's bridge linked Cardano and Ethereum for a family of related tokens, including FET, the shared token SingularityNET and Fetch.ai adopted when they merged their coins into the ASI Alliance in 2024. Its Ethereum side could not look at Cardano for itself. It trusted a messenger instead: a signing key, a secret code that works like a bank manager's signature, held on the company's own computers rather than on the blockchain. When that key signed a message saying "these tokens were burned on Cardano, release them here", the smart contract, code that moves money by itself, paid out. Bitquery counted five of these authoriser accounts across the affected bridges. None had ever sent a transaction of its own. They existed only to sign.

How one key printed money

Whoever holds that signature does not need to fake a deposit. They only need to tell the booth that a deposit happened. The security firm SlowMist identified the flaw at 02:47 UTC on 20 September. The converter's incoming payment function accepted one signature as its only check, never confirmed any burn on Cardano, and skipped the amount limit that applied in the other direction. That limit was 100 to 1,000,000 FET per conversion. The drain released 8.72 million in one go.

The other tokens followed the same logic. At 20:50 UTC on 19 September, 29 minutes after the FET drain, the attacker used NuNet's own minting permission to create 408.53 million NTX directly on the token. From 03:13 UTC on 20 September AGIX was printed in batches of 10 million. WMTX followed at 03:38. World Mobile's converter did cap each call, which only meant the attacker split the job into 503 calls. CGV was printed in 50 calls between 04:34 and 04:38. Bitquery's tally: 895.96 million AGIX, 408.53 million NTX, 500.48 million WMTX and 492.4 million CGV. By its count, unauthorised tokens made up 70.1% of all the AGIX it could measure and 81.1% of the CGV.

Before printing anything, the attacker had emptied 16 ordinary wallets in 21 minutes. Bitquery said four of them carried SingularityNET or NuNet staff labels, including the account that deployed the converters in 2022.

How the key leaked has only been described by the company. SingularityNET said on 22 September that "an unauthorized party gained access to part of our cloud infrastructure". Goertzel went further in a blog post on 30 September. He described old Amazon Web Services infrastructure "set up by some of SNET team members around 2018", and said it looked as if AI agents, chatbot-style programs set loose to work on their own, had found several small weaknesses and chained them together to reach the keys. He stressed that the forensic work was not finished.

Why $16.77M became $2.29M

PeckShield's $16.77 million was made of three things: 198.3 million AGIX valued at $14.42 million, 649 ETH at $1.67 million, and 33.54 million WMTX at $627,350. The ETH was real. The AGIX was priced at what the token traded for before hundreds of millions of new ones existed, which is like valuing counterfeit shares at the last price of the real ones. CoinMarketCap data showed AGIX falling from about 7.75 cents to under a tenth of a cent within roughly an hour. At that price the same 198.3 million AGIX was worth about $136,000.

©CMZ chart. Data: PeckShield, Rekt News, Bitquery

Every sale proved the point. A swap of 246.2 million CGV into Cogito's trading pool returned 0.0123 ETH, around $30. Ten million NTX fetched 940 USDT, another digital dollar. A batch of 100,000 WMTX brought 0.83 ETH.

Rekt's tally up to 22 September came to about 742.7 ETH and $362,075 in digital dollars, roughly $2.29 million. The biggest piece by far was the 522.78 ETH from the stolen FET, which was real and had real buyers. The payout contract supplied $289,575. Bitquery counted only about 184 ETH and $52,395 in digital dollars from selling the counterfeit tokens. On 25 September the attacker's two main wallets still held about 824 million AGIX, 200 million WMTX and 246 million CGV.

The paper number still hurt someone. About 40 million fake NTX crossed to Cardano and landed in ordinary trading pools, which cannot tell a counterfeit token from a real one. Traders and automated market makers who paid real money for printed AGIX, WMTX and NTX now hold tokens their issuers are disowning. NTX fell by between 65% and 90% depending on the tracker. WMTX lost about 43%.

Where the money went

The cash moved quickly. The blockchain tracing firm AMLBot reported on 22 September that one 100 ETH batch had been swapped for about 266,000 USDC, moved through Circle's transfer system to Arbitrum and into the trading platform Hyperliquid, and converted into something called "FXMR", likely a stand-in for Monero, a coin built to be hard to trace. A second 100 ETH batch was turned away by a Chainflip broker, so the attacker went to THORChain instead and came out with about 3.28 BTC. Three other wallets sent 75,000 USDC to Chainflip, 75,000 USDC to Baltex, a swap service that advertises no identity checks, and 118,015 USDC to Chainflip again. About 433 ETH was still sitting in the attacker's main wallet on 25 September. No firm has publicly attributed the attack to a named group.