Zombies flood broadband networks
Zombie compromised PCs are as fond of eating bandwidth as their counterparts are of munching through brains, according to a new study.
Arbor Networks' third annual worldwide infrastructure security report found that, for the first time, botnets surpassed distributed denial of service attacks as the top operational threat identified by service providers. Botnet networks of compromised PCs act as resources to distribute spam, launch denial of service attacks or get up to other forms of mischief.
Distributed denial of service (DDoS) attacks represent a major problem, with attack trends changing. While mid-level DDoS attacks have plagued the internet since 2000, survey respondents report a widening gap between common mid-level "amateur" attacks and multi-gigabit "professional" efforts involving tens of thousands of zombie hosts. Most surveyed ISPs reported significant improvements in the sophistication and coordination of DDoS attacks.
Surveyed ISPs reported sustained attack rates exceeding 24 Gbps. Most individual core internet backbone links today are no larger than 10 Gbps, which means most of the larger attacks inflict collateral damage on net infrastructures way upstream from the targets of attacks, Arbor notes.
Such attacks aren't all bad news for service providers. Many of them have turned DDoS detection and mitigation into a commercial service and growing revenue source. Which is nice, not least for Arbor, which markets DDoS mitigation gear. The number of service providers offering such "clean pipe" services is growing. More than one third of surveyed providers reported offering DDoS managed security services, with another third indicating they plan to roll out such services in the next two years.
Arbor's report, which is based on a worldwide survey of 70 of its tier-1 and tier-2 service providers' customers, also looked at the emerging threat posed by VoIP networks. It found only 20 per cent of ISPs surveyed have specific tools or mechanisms in place to monitor and detect threats against VoIP. VoIP and DNS (Domain Name Server) infrastructures are poorly protected, Arbor warns.
"Given that over half of the surveyed ISPs believe that they can effectively mitigate most internet attacks against their backbone infrastructure and customers, many ISPs now believe they are ahead of the curve," said Danny McPherson, Arbor Networks chief research officer. "But all of this ISP optimism about infrastructure security should be tempered by the survey data on emerging critical infrastructure. Over half of surveyed providers said they had no means to either detect or mitigate attacks against DNS, and close to 90 per cent have no means to protect critical VoIP infrastructure." ®