Looks like Santa visits cybercrooks too. Their present this year was a big, fat security hole in many widely used versions of Microsoft’s Internet Explorer. The critical vulnerability allowed remote code execution if an Explorer user visited a specially crafted, malicious Web page. That translated into the potential for big-time credit card fraud and identity theft. Considering the high volume of online retail going on this time of year, and the fact that Explorer happens the world’s most widely used browser, it amounted to a serious problem.