While the Soviet Union has been assigned to the history books, the web address associated with it is anything but history. The .SU domain was given to the (then) Union of Soviet Socialist Republics (USSR) in 1990, just a year before its dissolution. Since the domain was technically irrelevant after that people started using it for other things and now it is a hot bed for online scams and hackers.
When officials in Russia tightened the restrictions and laws governing the .RU domain names in 2011, people started to migrate to the less restricted .SU domain, where they could effectively do whatever they wanted and for the most part, still can.
The Russian internet watchdog agency Group-IB said they have found malicious websites double on the domain in 2011 to 2012 then double again this year, with high profile hack sites such as Exposed.su which published credit records of Michelle Obama, Mitt Romney, Donald Trump, Beyonce and others recently.
Moscow's Foundation for Internet Development has acknowledged this issue, but has said that the restrictions that his .RU will also be put into place to govern .SU in the future.