Number Of Malware-Infected Websites Tops 1 Million Mark

If you're wrestling with malware infections on your website, then you have company. Lots and lots of company.

According to a new report published in a blog today by researchers at security firm Dasient, the number of websites infected by malware in the second quarter of 2010 spiked to more than 1.3 million -- the first time that figure has ever topped 1 million.

"That's a jump of almost two times the number that we saw in the previous quarter," says Neil Daswani, co-founder of Dasient. "The numbers are really surprising."

Malware authors are becoming more efficient and creative in their methods of attacking websites, Dasient says. For one thing, they are creating new malware at an exceedingly rapid rate: Dasient detected more than 58,000 new infections in Q2 alone, raising its comprehensive malware library to more than 200,000 different infections.

Attackers are also becoming more crafty in the way they distribute their payloads, Daswani observes. For example, many malware authors have begun deploying new infections late on Friday afternoons, when they know most IT departmental resources will be at an ebb over the weekend.

"They can make the campaign last longer by starting it right before a weekend," Daswani says. The average malvertising campaign in Q2, for example, lasted 11.5 days.

Malvertising itself continues to grow, Dasient says: More than 1.6 million malvertisements are served on an average day, up 20 percent in the second half of Q2, according to the report. Some 42 percent of websites rely on third-party advertising resources, yet many site operators do not vet this content for malware before they serve it, Daswani notes.

Attackers favored JavaScript over iFrames as a means of delivering malware in Q2, according to the report. "In Q2, over 43,000 JavaScripts and over 15,000 IFRAMEs were added to Dasient’s infection library," Dasient says. "As a percentage of the total number of new entries, JavaScript samples have increased by 19 percent, and JavaScript samples now make up 74 percent of the entries for the quarter [as compared to 55 percent three quarters ago]."

"One of the advantages of JavaScript is that it can be used to modify a whole Web page, whereas an iFrame is more limited," Daswani says. "JavaScript offers a larger attack surface."

Attackers use .com and .cn domains most frequently to host malicious code, Dasient says. In Q2, there was a rise in .info domains that were infected and used to host malicious code, the report states.

Three out of four drive-by-downloads have one letter filenames and are written to the User's Application Data directory, according to Dasient. The most common name for a drive-by-download was f.exe.

The level of attack sophistication is going to only increase over time, Daswani says. "This is a problem that isn't slowing down," he says. "It's not going away."

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