On 22 July 2021, Transnet became a victim of a ransomware attack. The attack caused Transnet to declare force majeure at several key container terminals, including Port of Durban, Ngqura, Port Elizabeth and Cape Town. The attack was the first time that the "operational integrity of the country's critical maritime infrastructure has suffered a severe disruption" leading the Institute for Security Studies (ISS) to call its impact "unprecedented" in South African history.

The Port of Durban, commonly called Durban Harbour, is the largest and busiest shipping terminal in sub-Saharan Africa. It handles up to 31.4 million tons of cargo each year. It is the fourth largest container terminal in the Southern Hemisphere, handling approximately 4.5 million TEU in 2019.