Hackers attacked F Oil Refinery, owned by Tube. After gaining access to the enterprise's industrial control system, the attackers changed the settings of the rectification column, increasing the steam supply to the lower part of the column, which led to the formation of foam that prevented the liquid fractions from flowing down through the apertures in the plates. The column switched to flooding mode, filling up with oil and halting the separation of fractions. For several hours now, instead of the required gasoline, kerosene, and fuel oil, a substandard product has been coming out of the column.