Religion riskier than porn for online viruses: study

"Drive-by attacks" in which hackers booby-trap legitimate websites with malicious code continue to be a bane, the US-based anti-virus vendor Symantec said in its Internet Security Threat Report.

Websites with religious or ideological themes were found to have triple the average number of "threats" that those featuring adult content, according to Symantec.

"It is interesting to note that websites hosting adult/pornographic content are not in the top five, but ranked tenth," Symantec said in the report.

"We hypothesize that this is because pornographic website owners already make money from the Internet and, as a result, have a vested interest in keeping their sites malware-free; it's not good for repeat business."

The report was based on information gathered last year by the Symantec Global Intelligence Network, which monitors cyber attack activity in more than 200 countries through its services and sensors.

Symantec said that it blocked 5.5 billion attacks in 2011 in an increase of 81 percent from the prior year.