Attacks against PCs from hybrid worm/Trojan viruses have risen in the past few months.The hybrids combine the threats of worms and Trojans and can spread rapidly through unguarded email accounts or poorly defended PCs connected to the internet.A worm can transmit and make copies of itself over a computer network, such as the internet and differ from viruses because cannot attach themselves (or ‘infect’) other files, a key characteristic of viruses. Full Story