While there might be eartg life that can live in those extreme environments, that type of life usually can't live at what we consider more comfortable temperatures and couldn't survive being on the probe while it was on earth being loaded into s rocket etc. That's why even though there is life that thrives in the cknditions inside an autoclave (pressure/steam cookers used to sterilize things in labs or medicine), you don't have to worry about them since they can only survive in those conditions.