Symantec last week crippled a large number of Windows XP machines when it shipped customers a defective update to its antivirus software, the company acknowledged Friday. "After a full evaluation and root cause analysis ... we have determined that the issue was limited to machines running a combination of Windows XP, the latest version of the SONAR technology, the July 11th rev11 SONAR signature set, and certain third-party software," said Orla Cox, of the company's security response team in a July 14
blog post.