Feeds

Security firm chokes sprawling spam botnet

Mega-D no more

The essential guide to IT transformation

A botnet that was once responsible for an estimated third of the world's spam has been knocked out of commission thanks to researchers from security firm FireEye.

After carefully analyzing the machinations of the massive botnet, alternately known as Mega-D and Ozdok, the FireEye employees last week launched a coordinated blitz on dozens of its command and control channels. The channels were used to send new spamming instructions to the legions of zombie machines that make up the network.

Almost immediately, the spam stopped, according to M86 Security blog. Last year, the email security firm estimated the botnet was the leading source of spam until some of its servers were disabled.

The body blow is good news to ISPs that are forced to choke on the torrent of spam sent out by the pesky botnet. But because many email servers already deployed blacklists that filtered emails sent from IP addresses known to be used by Ozdok, end users may not notice much of a change, said Jamie Tomasello, an abuse operations manager at antispam firm Cloudmark.

The takedown effort is significant because it shows that a relatively small company can defeat a for-profit network that took extraordinary measures to ensure it remained operational. Not only did Ozdok reserve a long list of domain names as command and control channels, it also used hard-coded DNS servers. When all else failed, its software was able to dynamically generate new domain names on the fly.

With head chopped off of Ozdok, more than 264,000 IP addresses were found reporting to sinkholes under FireEye's control, an indication of the massive number of zombies believed to have belonged to the botnet. FireEye researchers plan to work with the ISPs to identify the owners of the orphaned bots so their owners can clean up the mess.

FireEye researchers said the key to dismantling the giant ring was a coordinated effort that worked in multiple directions all at once so that bot herders didn't have a chance to counteract. "As it turns out, no matter how many fallback mechanisms are in place, if they aren't all implemented properly, the botnet is vulnerable," they wrote. ®

Next gen security for virtualised datacentres

More from The Register

next story
Ice cream headache as black hat hacks sack Dairy Queen
I scream, you scream, we all scream 'DATA BREACH'!
Goog says patch⁵⁰ your Chrome
64-bit browser loads cat vids FIFTEEN PERCENT faster!
NIST to sysadmins: clean up your SSH mess
Too many keys, too badly managed
Scratched PC-dispatch patch patched, hatched in batch rematch
Windows security update fixed after triggering blue screens (and screams) of death
Researchers camouflage haxxor traps with fake application traffic
Honeypots sweetened to resemble actual workloads, complete with 'secure' logins
Attack flogged through shiny-clicky social media buttons
66,000 users popped by malicious Flash fudging add-on
New Snowden leak: How NSA shared 850-billion-plus metadata records
'Federated search' spaffed info all over Five Eyes chums
Three quarters of South Korea popped in online gaming raids
Records used to plunder game items, sold off to low lifes
Oz fed police in PDF redaction SNAFU
Give us your metadata, we'll publish your data
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Backing up Big Data
Solving backup challenges and “protect everything from everywhere,” as we move into the era of big data management and the adoption of BYOD.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?