They've been happily surviving in a briny pool approximately 5 kms wide, sealed more than 1,300 feet below the glacier ice for millions of years.
They've adapted to 'breathe' iron to produce energy and were discovered in the water slowly leaking from the glacier where the pools are buried. This water flows erratically and it's taken researchers years to collect enough to test.
The very salty water which doesn't freeze because of its extreme saltiness, was devoid of oxygen but loaded with elements of iron and sulphur.
Two species of living microbes have been cultured, Thiomicrospira arctica, which metabolizes sulphur and Desulfocapso sulfoexigens, which can live without oxygen but it's not yet known how many different species are living in the pool itself. Life forms like these are called extremophiles and many think these are what will be discovered on the planets in our solar systems.
Antarctica, alien virus, X-files, you all remember those episodes, don't you?