Apostle is a .NET based malware that evolves from a Wiper to full-featured ransomware. It shares code with another tool from Agris APT arsenal, IPsec Helper.
CoViper is just another threat actor that wants a piece of the pie of the COVID-19 outbreak. CoViper is a Master Boot Locker or MBRLocker. It means it does not encrypt user files but change the Booting "sequence" and hence render a system useless. An advanced computer user can recover it by installing a new MBR.
This Wiper is named as GermanWiper due to its targeting of German victims and it is a destructive wiper rather than ransomware. It destroys its victim's files by filling zeros in it and yet ask for 0.15 BTC or $1500.
Olympic Destroyer as the name implies is a malware / worm designed for destruction and sabotage the of on going Winter Olympic games in Pyeongchang, South Korea.