Cybercriminals are taking a page from the software-as-a-service textbook: they're now selling exploit kits complete with hosting services, with customers paying for the length of time the exploits are actively infecting computers.
The kits offer several kinds of exploits, or sequences of codes that can take advantage of software vulnerabilities in order to deliver malware. Researchers from Seculert have found that at least a couple of these kits - Incognito 2.0 and Bomba - offer their own web hosting as well as a web-based management interface.
The new business model makes it easier for cybercriminals who may have trouble securing so-called "bulletproof" hosting, or ISPs willing to host malware servers, said Aviv Raff, CTO and co-founder of Seculert. The company specialises in a cloud-based service that alerts its customers to new malware, exploits and other cyberthreats.
The whole package is intended for criminals who want large numbers of hacked computers running Microsoft Windows. Once the computers are hacked, the machines can be used to steal personal data, send spam, for conducting denial-of-service attacks or other purposes.
It's also cheaper. The criminal clients pay for only the time that their exploits are live, meaning if for any reason the ISPs shut down the rogue servers, they don't have to pay, Raff said. He estimated the malware hosting and exploit service to cost between $100 to $200 a month.
"This is all managed by the 'service provider'," Raff said. "You as a customer only pay for the time the exploits are hosted. We don't have the exact numbers, but like any other 'cloud-based' service, it's reasonable that the account is much more affordable than buying the kit and hosting it."
The clients must provide their own malware for the exploits to deliver. They must also hack websites in order to redirected victims to the crimeware servers hosted by Incognito's operators. When a potential victim visits one of the infected websites, an iframe is displayed that brings in content from Incognito servers that starts trying to hack the machines with various exploits.
So far, Seculert counted about 8,000 legitimate websites that have been hacked and are pulling exploits hosted by Incognito. Some victims are infected when they go to those sites through normal browsing, Raff said. But the hackers have also used spam campaigns to try to draw people to infected sites.
One of those recent spam messages noticed by Seculert purported to be a support message from Twitter, which encouraged people to click on a link that was supposedly a video from near the ailing Japanese nuclear reactors in Fukushima damaged in the tsunami earlier this month. If a person clicked on the link, no video was displayed, and a Trojan downloader was installed on the computer if it had a software vulnerability.
Incognito 2.0 provides a web-based management interface where clients can check how many computers have been infected and what type of exploit was used, Raff said. Seculert posted screenshots on its blog.
Incognito 2.0 seems to be a growing business: Seculert's researchers found after analysing its infrastructure that at least 30 clients were using it to install everything from the Zeus banking Trojan to fake antivirus software to generic Trojan dowloaders that can install other malware on an infected computer.
At least 150,000 machines were infected during a two-week period in January. About 70 percent of those computers were infected using an exploit for a vulnerability for the Java runtime environment, with 20 percent infected via an Adobe Reader vulnerability.