Beleagured instant-update sharing site Twitter is also in the news this month after it came to light that it is being used to control large swathes of infected computers around the world. The Trojan Down loader.Sninfs infects computers, after which they start periodically checking designated Twitter accounts for instructions, according to Semantic and Arbor Networks. These accounts contain posts which are nothing but base64-encoded strings containing links to URLs where even more malicious code is waiting to be downloaded.

This code is what contains the instructions or additional Trojans including one known as Info steal.Ban cos which attempts to capture passwords to banking sites. Several public Web services including forums and instant messengers have been used in the past to control and issue instructions to bonnets, but this is the first known use of Twitter for the same purpose. The discovery highlights just how easily any new technology can be used for positive or negative purposes. Millions of infected PCs make up the world's bonnets, largely unknown to their owners. These computers are then used to spread viruses and spam, and carry out distributed denial-of-service attacks much like the one that took down Twitter itself this month as well. Botnets rely on central nodes to issue commands.