FireEye moves quickly to quash Mega-D botnet

The security company contacted ISPs and registrars to help shut down the spam-spewing botnet

A computer security company known for battling botnets moved last week to try to shut down a persistent spam player.

FireEye, a California company that makes security appliances, had been tracking a botnet called Mega-D or Ozdok. Mega-D, which is a network of hacked computers, has been responsible for sending more than 4 percent of the world's spam, according to M86 Security.

Many of the computers that make up Mega-D are infected home PCs.

Mega-D is one of several botnets that have implemented advanced technical measures to ensure its owners don't lose control of the hacked PCs. The hackers use command-and-control servers to issue instructions to the zombie PCs, such as when to run a spam campaign.

In the case of Mega-D, the hacked PCs will look for certain domain names in order to download instructions, wrote Atiq Mushtaq of FireEye on the company's blog.

If those domains aren't active -- they are often shut down by ISPs if they're associated with abuse -- Mega-D machines will look for custom DNS (Domain Name System) servers to find live domains.

If that also fails, Mega-D is programmed to generate a random domain name based on the current date and time, Mushtaq wrote. When the hackers register the domain name, the infected machines can visit there to get new instructions.

Mega-D's mechanisms to ensure it stays alive have made it difficult for security companies. "Unless someone is committed enough to pre-register those domains, the bot herders can always come forward and register those domains and take the botnet control back," Mushtaq wrote.

Last Thursday night, FireEye started its assault, contacting ISPs that had machines acting as command-and-control servers for Mega-D. All but four service providers shut down connections for IP addresses used by Mega-D, Mushtaq wrote. FireEye also contacted the registrars that control domain names used for Mega-D.

As a final measure, FireEye registered the auto-generated domain names that infected Mega-D computers would contact if the machines failed to reach other command-and-control nodes.

Mushtaq wrote on Friday that some 264,784 unique IP (Internet Protocol) addresses had contacted FireEye's "sinkhole" server, or a server set up in order to identify infected PCs.

"Data collected from the sinkhole server logs will be used to identify the victim machines," Mushtaq wrote.

It's hoped that ISPs will then contact those subscribers and inform them that they need to run an antivirus scan.

FireEye's efforts, along with the cooperation of ISPs and registrars, appear to have successfully tamed Mega-D, at least temporarily.

On Monday, statistics from M86 Security showed that Mega-D spam had nearly stopped.

At one previous point, M86 had seen a single Mega-D infected computer send as many as 15,000 spam messages per hour.

"It clearly shows that it's difficult but not impossible to take down some of the nastiest botnets of the world," Mushtaq wrote.

But the reprieve may not last long. FireEye was pre-empting Mega-D by registering domains the bots would look for, but that process can be never-ending and expensive. If FireEye stops registering domains and the orphaned bots call home, the hackers could upload new code to them to make them more difficult to shut down.

"We are unsure how long we can keep up with these future domains," Mushtaq wrote.

Join the newsletter!

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

Tags mega-dbotnetssecurityFireEye

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

Jeremy Kirk

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

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.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Matthew Stivala

HP OfficeJet 250 Mobile Printer

The HP OfficeJet 250 Mobile Printer is a great device that fits perfectly into my fast paced and mobile lifestyle. My first impression of the printer itself was how incredibly compact and sleek the device was.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?