SignalPlus said attackers compromised an engineer’s computer in a breach that resulted in losses of less than $82,000, which the crypto trading platform pledged to reimburse in full. Exchanges Binance and Deribit said Thursday they had revoked API keys connected to crypto derivatives trading platform SignalPlus as a precaution following a security breach. Both exchanges said their own systems were unaffected, while Deribit warned that trading, monitoring and automation through SignalPlus had stopped working for its customers.