{
  "id": 7563600,
  "title": "A hacker turned 25 cents of bitcoin into 46 billion fake BTC tokens on a DeFi bridge",
  "url": "https://urgent.news/2026/09/15/a-hacker-turned-25-cents-of-bitcoin-into-46-billion-fake-btc-tokens",
  "topic": "finance",
  "section": "Finance & Markets",
  "published": "2026-09-15T13:43:50.000Z",
  "source": {
    "name": "CoinDesk",
    "slug": "coindesk",
    "url": "https://www.coindesk.com/tech/2026/09/15/a-hacker-turned-25-cents-of-bitcoin-into-46-billion-fake-btc-tokens-on-a-defi-bridge"
  },
  "original_language": "en",
  "account": "A 25-cent Bitcoin deposit fueled the creation of 46 billion counterfeit BTC tokens on Symbiosis, a cross-chain application. The breach occurred due to two software flaws working in tandem. The vulnerability allowed the attacker to manipulate the system's understanding of a bitcoin transaction, granting them the role of both a depositor and bridge administrator. This elevated access enabled the attacker to set the bridge's minimum fee below zero. A second flaw then inflated the deposit's value, making it appear to represent a substantial amount of Bitcoin. Before the attack, the syBTC supply was just 13.91 tokens, with 11.26 syBTC locked in liquidity pools. The attacker stashed away roughly $9.97 million worth of Bitcoin, valued at approximately $770,000. The discrepancies between the fabricated tokens and actual losses arise from the unbacked nature of these bridge tokens, meaning they lack the real assets required for redemption. Symbiosis, which currently holds around $8 million in total value locked, stated it would cover the stolen funds using some of the Bitcoin evacuated during the attack and compensate affected liquidity providers via separate channels. The bridge remains offline while the Bitcoin-side software undergoes rewriting and independent auditing. The incident also highlights the evolving security landscape, where AI-driven software vulnerabilities are becoming more accessible and affordable to exploit.",
  "summary": "Two software bugs allowed the attacker to create more than 2,000 times Bitcoin’s maximum supply in unbacked syBTC. Symbiosis puts preliminary losses at 9.97 BTC.",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}