I have never in my life heard about cyber Monday. The only thing I have heard about is black Friday and I think it is also the most popular way of giving discounts to people who want to buy things and it is especially or mostly done by big companies or bigger platforms.
I also do not think the act of cyber Monday is practiced here in my country because it is something that is very rare or never even heard about but I will make my findings and thank you very much for letting us know about cyber Monday