Computest Sector 7 was asked by Team High-Tech Crime of the Dutch Police to help with writing a decryptor for the DoNex/DarkRace ransomware. DoNex is a relatively new ransomware group, which probably explains why its encryptor contains a simple to abuse mistake. It appears to be the same group that was working under the name DarkRace last year, as the DoNex encryptor we investigated is essentially the same as a DarkRace encryptor we looked at.