Top 5 Botnets and 5 Steps to Avoid

Wednesday, July 1, 2009

The Top 5 Botnets and 5 Steps to Prevent Your Computer from bot-icipating.

According to the latest MessageLabs Intelligence Report, botnets are responsible for over 83% of all spam. Here's a list of the Top 5 Botnets... (compiled by Net Security.org)

Cutwail - 45% of all Spam

The largest and most powerful botnet is responsible for 45% of all spam. With between 1.5 and 2 million active bots, Cutwail was perhaps the largest botnet in history at its peak. "Cutwail's recovery to one-third of its original levels, after only a few hours, highlights the progress spammers have made since the McColo shutdown in November," said Paul Wood, MessageLabs Intelligence Senior Analyst, Symantec. "Spammers have learned the importance of having a backup for command and control channels."

Mega-D - 9.3%

Sounding more like a performance enhancing supplement than a botnet, this was the top botnet at the start of the year, but has been steadily decline to the point that it is now responsible for only 9.3% of spam. However, it's still one of the hardest working botnets in terms of spam per bot per minute.

Xarvester - 0.2%

Should be called X-Harvester, because although it was one of the major botnets of the year, it has drastically reduced in size and output, and now is responsible for sending out 0.2% of spam.

Donbot - 3.2%

A top 5 botnet in size and output, it's been less active in recent months sending out 3.2% of spam

Grum and Rustock - 10%

These newer (but very large) botnets are a wildcard. Combined, they're responsible for over 10% of spam, but their activity is hard to predict: both send spam in bursts, with Rustock often going through periods of zero activity.

Source: June 2009 MessageLabs Intelligence Report.