One bot-infected PC = 600,000 spam messages a day

Rustock, Xarvester top the list as most efficient spam-spewing bots

Some bot-infected PCs can crank out as many as 25,000 spam messages per hour, new research released Wednesday claimed.

California-based Marshal8e6 deliberately infected machines in the lab of its research arm, TRACElabs, with the malware responsible for the world's nine biggest spam botnets, then observed the PCs' behavior, including each bot's top-end spam capacity.

"One of the our objectives over the past few years has been to emphasize the dominant role that a handful of key botnets play in the spam we see today," said Phil Hay, a senior threat analyst with TRACElabs, in an e-mail today.

TRACElabs concluded that Rustock and Xarvester, the latter perhaps linked to the down-and-out Srizbi botnet, are the most efficient spam-spewers of the nine bots. Each is capable of sending up to 25,000 messages per hour, or 600,000 per day, and 4.2 million per week.

The next-most effective spam bot, said TRACElabs, is Mega-D, one of the bots that took advantage of the November 2008 takedown of McColo Corp., a hosting company that harbored the command-and-control servers for several big botnets, including Srizbi and Rustock.

When McColo's connection to the Internet was severed by its upstream providers -- in large part because of investigative work done by security researchers such as Joe Stewart, director of SecureWorks Inc.'s counterthreat unit -- spam volumes plunged as botnet controllers couldn't tell hijacked PCs what to do. Since then, however, spam has essentially returned to pre-McColo levels as a bot master resuscitated damaged botnets or unaffected botnets picked up new spamming customers, and thus the slack.

Some well-known names rated relatively low on TRACElabs' list. Waledac, which analysts have said is a successor to 2007-08's Storm bot, was recently in the news when it was installed by PCs infected with the Conficker worm. The botnet can cough up 7,000 messages an hour, or 168,000 a day.

According to TRACElabs, Rustock bots were responsible for 26% of the spam generated in the first quarter of 2009, with Mega-D and Pushdo not far behind at 22% and 18%, respectively. The other efficient bot -- Xarvester -- held fourth place, accounting for just 8% of all spam.

Today's revelations aren't the first to note that some botnets are far more efficient at spamming than others. In a botnet census he conducted a year ago this month, SecureWorks' Stewart said that Srizbi -- later the biggest loser in the McColo takedown -- was capable of delivering 60 billion spam messages per day.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags botnetsphysical securityspamMarshal8e6

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Gregg Keizer

Show Comments



Victorinox Werks Professional Executive 17 Laptop Case

Learn more >

Sansai 6-Outlet Power Board + 4-Port USB Charging Station

Learn more >



Back To Business Guide

Click for more ›

Most Popular Reviews

Latest Articles


PCW Evaluation Team

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?