The owner of an address associated with the wave of spam attacks that took place on Ethereum last year is sending commands meant to use up 'gas', ethereum's unit of computational power. However, the attack was quickly spotted by the community. Within an hour, the popular Go implementation released a new version called 'Hat Trick', complete with a security fix that changed the structure of some types of data that were being utilized in the new attack.
source: https://pixabay.com
Read more: http://www.coindesk.com/ethereum-developers-stymie-blockchain-spammers-latest-attack/