Complex sentence: The DDoS attacks during the October 2011 South Korean by-election consisted of two separate denial-of-service attacks (DDoS) against two websites during the October 2011 by-election, on October 26th, 2011.
Split into simpler sentences: The DDoS attacks during the October 2011 South Korean by-election were two separate denial-of-service attacks (DDoS) during the October 2011 by-election. The attacks consisted of two separate denial-of-service attacks against two websites during the October 2011 by-election, on October 26th, 2011.