It didn't find evidence of even the simplest, organic molecule. Since then, some members of the Viking team have questioned whether they missed something in that initial analysis. But to this day, there's no accepted evidence of microbial life on Mars.
Most recently, and possibly most excitingly, researchers have found the first evidence of an existing body of liquid water on Mars. It was found using radar and this is a sub-glacial lake under the southern polar ice cap of the red planet.