On September 11, 2024, Omnipus presale contracts were exploited for approximately $30,000 when a commented-out check in OAppSender.sol's payNative() function allowed attackers to bypass validation. The contract mistakenly refunded ETH to attackers who claimed overpayment, enabling unauthorized fund extraction.

Omnipus contracts were drained of approximately $30,000 during the OPUS token presale. The attack exploited a vulnerability in which the contracts mistakenly believed the attackers had sent too much ETH and refunded them.