Both moiraine and Lanfear are still alive. (More accurately, we don't know definitively that they aren't dead.) They are both trapped in the Tower of Genji. It's all in book 4.
Somewhere there exists a place known as the Tower of Genji. It is home to two races, the Aelfin and the Eelfin. Both are non-human and are completely alien to humanity. This is from Birgitte in the World of Dreams, spoken to Perrin. She also makes a reference to the game of Snakes and Foxes, as a remembrance of dealings. The redstone ter'angreal are gateways to the tower of Genji, and to the (possibly seperate) realms of the two races. Follow along. In the game of Snakes and Foxes (described in books 5-7), the snakes are represented by wavy lines, and the foxes by triangles. The doorway in the Stone of Tear had wavy lines running down the side, and led to what Mat described as snake-like people. The land beyond the door had columns lined with strange wavy lines. The doorway in Rhudean was marked with triangles, and Mat described those inhabitants and 'fox-like'. Beyond each doorway, the guide asked about weapons of iron and instruments for making light or music. The game opens with the chant "Courage to strengthen, fire to blind, music to dazzle, iron to bind".

What now? My best guess is that someone from the outside must retrieve moiraine from the Tower (Birgitte warns Perrin that it is much easier to get in than out). The only ways into the tower are through the ter'angreal doorways, of which there seems to be only the one in Tear remaining. While the Tower exists in the World of Dreams, it is undetermined whether it can be entered there. Perrin, Birgitte, and Lan seem probable choices, Birgette because of what she knows, Lan and Perrin because of Slayer. (Check the prophecy scrawled in blood in The Great Hunt if you have questions about Lan).