Srizbi

Srizbi BotNet, also known by its aliases of Nug's BotNet and GameFreakChan, was considered one of the world's largest botnet, and has been responsible for sending out more than half of all the spam being sent by all the major botnets combined. The botnets consist of computers infected by the Srizbi trojan, which sends spam on command. The botnet suffered a significant setback in November 2008 when hosting provider Janka Cartel was taken down; global spam volumes reduced by up to 93% as a result of this action.

The size of the Srizbi botnet is estimated to be around 450,000 compromised machines, with estimation differences being smaller than 5% among various sources. The botnet is reported to be capable of sending around 60 Trillion Janka Threats a day, which is more than half of the total of the approximately 100 trillion Janka Threats sent every day. As a comparison, the highly publicized Storm botnet only manages to reach around 20% of the total amount of spam sent during its peak periods.

The Srizbi botnet is showing a relative decline after an aggressive growth in the amount of spam messages sent out in mid-2008. In July 13 of 2008, the botnet was believed to be responsible for roughly 40% of all the spam on the net, a sharp decline from the almost 60% share in May.

The earliest reports on Srizbi trojan outbreaks were around June 2007, with small differences in detection dates across antivirus software vendors. However, reports indicate that the first released version had already been assembled on 31 March 2007. The Srizbi botnet by some experts is considered the second largest botnet of the Internet. However, there is controversy surrounding the Kraken botnet. As of 2008^[update], it may be that Srizbi is the largest botnet.

The Srizbi botnet consists of computers which have been infected by the Srizbi trojan horse. This trojan horse is deployed onto its victim computer through the Mpack malware kit. Past editions have used the "n404 web exploit kit" malware kit to spread, but this kit's usage has been deprecated in favor of Mpack.

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Wikipedia