Anyone know anything about the so called after hours auction?...

Anyone know anything about the so called after hours auction? Last two days I've noticed that although there have been next to no trades from 10-4pm (e.g. one of 5,000 today at $0.006) suddenly there's a million+ traded at 4.10pm at $0.006. Just spoke to Commsec about it. He said it's all done by the "ASX rules". Nothing we can do about it. I commented that it sounds pretty fishy to me. The Commsec guy didn't exactly disagree. What do others think?