Microsoft last October cited Adobe Flash files as a growing medium for malware distribution.
The trend was also noted by Finjan, a security company. "We have started to see 'in the wild' cases where Flash-based ads are being used by cybercriminals," Finjan's Q4 2008 Web Security Trends Report states. "Due to the simplicity of these techniques, we believe it will evolve into a major trend in 2009."
Boscovich said that malvertising "is definitely an emerging threat. We're seeing more of it."
Malveristing presents a problem to companies that depend on online advertising because its existence justifies the use of ad blocking software. Approximately 1% of Internet users worldwide -- 5% of Firefox users -- use ad blocking software. If that number grows in response to an increase in malvertising, online ad revenue is likely to suffer.
As Microsoft's Cranton put it, "This work is vitally important because online advertising helps keep the Internet up and running. It's the fuel that drives search technologies. It pays for free online services like Windows Live, Facebook, Yahoo and MSN. Fraud and malicious abuse of online ad platforms are therefore a serious threat to the industry and for all consumers and businesses that rely on these free services."
Boscovich advises users to keep their antivirus software up-to-date and to install operating system updates. "And don't provide any personal information to Web sites that you're not sure of," he said.
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