A Peek at ISP DDOS, Spam Traffic Trends

Here’s another perspective on the rise in malicious Internet traffic: Nearly 5 percent of all Internet traffic among ISP domains consists of either DDOS or spam, according to preliminary statistics gathered by Arbor Networks of around 70 of its ISP customers.

And there’s an average of 1,300 distributed denial-of-service attacks occurring each day, according to data gathered by Arbor over the past year and a half via its Atlas program.

Five percent may not sound like a lot at first glance, but it’s a disturbing statistic when you put it into context, according to Danny McPherson, chief research officer with Arbor. “How much junk would you allow in your drinking water? Or, if you could improve service or margins or download speeds by 5 percent, what would that mean to your business?”

Arbor has been working with 68 ISPs under its Atlas program, gathering network and transport layer traffic data -- inter-domain, rather than ISP customer or internal traffic. The data comes from around 1,300 routers and 100,000 interfaces, according to Arbor, with peak traffic rates close to 1.5 Tbit/s.

DDOS attacks accounted for around 1 to 3 percent of all of this traffic (not including spam, phishing, or other malicious traffic). SMTP email in Port 25, meanwhile, is about 1 to 1.5 percent of ISP inter-domain traffic, according to Arbor’s findings. And over half of that is likely spam, according to McPherson, so that makes nearly 4 percent of all inter-domain traffic “junk,” although Arbor has seen spikes up to 5 percent at times.

McPherson says Arbor also found that nine of the 10 most frequently attacked DDOS targets were IRC servers -- “ego-driven” attacks mostly. The most common DDOS attack vectors are TCP SYN flood attacks, with ICMP floods as the second most common.

And in case you were wondering, cybercriminals do take holidays: “Attack frequency seems to drop significantly on Christmas Day, New Year’s Eve, and New Years Day (perhaps while the miscreants are either hung over or expending their spoils),” McPherson wrote in a blog post yesterday.

Arbor plans to issue a formal, more detailed report in the next few months on malicious traffic trends ISPs are experiencing.

Have a comment on this story? Please click "Discuss" below. If you'd like to contact Dark Reading's editors directly, send us a message.