The privacy-focused cryptocurrency Monero has suffered a 51% attack, with Qubic claiming that the action was a technical demonstration rather than a malicious attack. Qubic, a project by IOTA co-founder Sergey Ivancheglo, rapidly accumulated a large amount of Monero (XMR) hash power through its "useful proof of work (uPoW)" mechanism, soaring from less than 2% to over 27%, briefly becoming the largest Monero mining pool. They publicly stated that their goal was to reach over 51% to test network security. On August 12, Qubic briefly controlled 52.72% of the Monero network's hash rate (approximately 3.01 GH/s). Once exceeding 51%, Qubic could reject blocks from other mining pools, leading to chain reorganization, double spending, or transaction censorship. The Monero community has launched resistance and defense actions, while Qubic claims this move is a technical demonstration, not a malicious attack. Ledger's CTO stated that Monero seems to be experiencing a successful 51% attack. The Qubic mining pool has been steadily accumulating hash power for months and now controls a significant portion of the network's hash power. This morning, a major chain reorganization was detected. With its current hash power, Qubic can rewrite the blockchain, implement double spending, and censor any transactions.