Criminals are stepping up their attacks leveraging an unpatched flaw in Microsoft's Internet Explorer browser, using it to install fake antivirus products and malicious back doors on victim's computers.

Microsoft first warned of the bug on March 9, saying that it had been used in "targeted attacks." But now, according to researchers, the exploits are much more widespread. By late last week, security vendor AVG was getting reports of 30,000 attacks per day, according to Roger Thompson, AVG's chief research officer.
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Security companies warn of uptick in attacks using new IE flaw | Security Central - InfoWorld