Hosting firm takedown bags 500,000 bots
The shutdown of McColo knocks out a record number of bots, says researcher
Computerworld - The shutdown last week of a U.S.-based Web hosting company crippled more than 500,000 bots, or compromised computers, which are no longer able to receive commands from criminals, a security researcher said today.
Although the infected PCs are still operational, the previously-planted malware that tells them what to do can't receive instructions because of the shutdown last week of McColo Corp.
McColo was disconnected from the Internet by its upstream service providers at the urging of researchers who believed the company's servers hosted a staggering amount of cybercriminal activity, including the command-and-control servers of some of the planet's biggest botnets. Those collections of infected PCs were responsible for as much as 75% of the spam sent worldwide. When McColo went dark, spam volumes dropped by more than 40% in a matter of hours.
The McColo takedown resulted in a record number of bots being severed from their hacker controllers by any single event, Stewart said. He compared it to last September, when Microsoft Corp.'s anti-malware utility, the Malicious Software Removal Tool (MSRT), purged nearly 300,000 infected PCs of the infamous Storm Trojan horse.
"That had a good impact, but it didn't stop the flow of spam globally," Stewart said of the MSRT takedown. "It didn't make a difference to other botnets that were still spamming away."
Knocking McColo offline, on the other hand, disrupted at least two major botnets -- "Rustock" and "Srizbi" -- and caused spam to plummet around the globe, said Stewart.
Stewart, a leading authority on botnets, estimated the strength of the top 11 botnets last April. Srizbi, at 315,000 bots, was No. 1 in his census, while Rustock, at 150,000, was in the No. 3 spot.
Rustock's handlers may never recover control of their bots, said Stewart. "It does look like they're lost to them," he said, noting that those bots lack a fail-safe for reconnecting with a command-and-control server if it does dark, as happened when McColo's plug was pulled.
But while Rustock's bots may be orphaned, there's a chance the Srizbi's bots can be brought back under control. "When Srizbi bots can't connect, as a backup, they're coded to try other domain names," to search for new command-and-control servers, said Stewart. Those domains, however, were recently registered, perhaps pre-emptively by a security researcher who had rooted through the Srizbi code.
"They're not receiving new instructions," Stewart said. That would indicate that a third party -- someone who didn't have the Srizbi source code, and thus a way to figure out the protocols for sending new orders to the disconnected bots -- may have snatched up the domain names.
- Massive botnet returns from the dead, starts spamming
- Spam levels fluctuate as crooks try to revive botnets
- Spam is silenced, but where are the feds?
- Dodgy ISP McColo briefly comes online, updates botnet
- McColo shutdown forces botnets to relocate
- Hosting firm takedown bags 500,000 bots
- Spam plummets after Calif. hosting service shuttered
- McColo takedown: Internet vigilantism or online Neighborhood Watch?
- IT Blogwatch: McColo is McShut McDown
- EndPoint Interactive eGuide In this eGuide, Network World, Computerworld, and CIO examine two endpoint trends - BYOD and collaboration - and offer tips and advice on...
- Mobile First: Securing Information Sprawl Learn how the partnership between Box and MobileIron can help you execute a "mobile first" strategy that manages and secures both mobile apps...
- Cybersecurity Imperatives: Reinvent your Network Security The Rise of CyberSecurity
- Surescripts Case Study- Securing Keys and Certificates Surescripts implemented Venafi's Trust Protection Platform™ to secure digital keys and certificates, ensure the privacy and confidentiality of electronic clinical information for its...
- Responding to New SSL Cybersecurity Threat The featured Gartner research examines current strategies to address new SSL cybersecurity threats and vulnerabilities.
- Deep Dive into Advanced Networking and Security with Hybrid Cloud Security and networking are among the top concerns when moving workloads to the cloud. VMware vCloud® Hybrid Service™ enables you to extend your... All Security White Papers | Webcasts
Our new bimonthly Internet of Things newsletter helps you keep pace with the rapidly evolving technologies, trends and developments related to the IoT. Subscribe now and stay up to date!