On July 2, 2021, XDX Swap on the HECO chain was exploited via a suspected backdoor in the cross-chain decentralized exchange code, allowing an attacker to extract approximately $176K (85.17 ETH). Most funds were subsequently recovered with support from Star Labs and the HECO White Hat Security Alliance.

The XDX Swap (DDEX) on the Heco chain's cross-chain decentralized exchange DDEX was attacked. The attacker made a profit of 85.17 ETH (approximately $176,000) and cross-chained it to Ethereum. The DDEX code appears to have a backdoor. With the support and cooperation of DDEX, Star Labs, and HECO White Hat Security Alliance, XDX Swap has successively recovered most of the funds involved in this attack, with a total value of more than 5 million US dollars.