Mass Effect - The Collector War
The planet Alchera, located in the Amada system of the Omega Nebula, is an icy ball deemed unsuitable for colonization due to its freezing climate and lack of natural resources. However, its three moons have all, at one time or another, been temporary homes for various mercenary bands and other organizations in the Terminus systems.
Current intel indicates that no such groups have been using the planet or its moons as a base of operations, but there have been rumors around the Terminus systems and Omega that, after the Battle of the Citadel, geth survivors escaped through the mass relays and were sighted in orbit around Alchera. Whether this report is accurate or not remains to be seen.