ORLANDO - If your system gets infiltrated by a rootkit, you might as well just "waste the system entirely," a Microsoft official told fellow security professionals last week at the annual InfoSec Conference here.Microsoft's\u00a0Mike Danseglio, program manager in the company's security solutions group, was among a host of security experts from big-name companies who swapped advice about protecting networks with 1,700 showgoers.According to Danseglio, the hacker rootkit is "probably the nastiest piece of malware you'll get," because it is designed to hide unwanted files - or any sign a computer has been compromised - stealthily.Microsoft dedicates four staffers to analyze rootkit samples found in customer computers or on the Internet. In his presentation, Danseglio offered a list of the most-wanted rootkits (see graphic), adding that 90% of what Microsoft finds relates to Hacker Defender, a rootkit from the Czech Republic-based programmer who calls himself Holy Father. The programmer charges several hundred dollars to make Gold versions of his basic rootkit.Writing rootkits isn't a crime, but using them to hide code in a computer that's been hacked by other means is, Danseglio said. Holy Father last month indicated he's retiring from his Web site business, leading some to speculate that he's been hired for some purpose somewhere.According to Danseglio, rootkits have been embedded in many networks, with college campuses especially hard-hit. The University of Washington has become notorious for its students using rootkits to hide pornography and music on the university's servers, he said.Danseglio offered a list of tools, including a few from Microsoft, that can detect rootkits. But he said there are no simple ways to address the menace. "There are no rootkit-resistant operating systems," Danseglio said.Lessons sharedKerry Anderson, a Fidelity Investment Brokerage vice president in the information security group, spoke on the topic of setting up a computer forensics program to tackle crime, including child pornography, terrorism and financial fraud.Microsoft's most-wanted listRootkits that hide in Windows:\u2022Hacker Defender\u2022FU\u2022HE4Hook\u2022Vanquish\u2022AFX\u2022NT RootkitTools that can detect rootkits:\u2022PatchFinder2 and Klister\/Flister, proof-of-concept tools from Polish researcher Joanna Rutkoska\u2022RootkitRevealer from Sysinternals\u2022Blacklight from F-Secure\u2022Microsoft File Checksum Integrity Environment\u2022Bootable Antivirus & Recovery Tools from Alwil Software\u2022Knoppix Security Tools Distribution (open source)A company's first priority should be establishing a policy and internal training for auditing and investigating suspected computer crime, coordinating among the legal, human resources and IT departments, she said.She advised extending that policy to include working with outsourcing providers, vendors and business partners to ascertain their computer-investigation procedures and get the right to audit and monitor their computers if necessary. "Our contracts today are requiring the right to do risk assessment and visitation audits," she pointed out.The insider threat is a top concern at State Street, which manages more than $10 trillion in assets. State Street Senior Technology Officer Doug Sweetman said securities laws require the firm to conduct background checks on employees and prospective employees.But these days, that might go beyond a criminal-history check and include scouring the Web to find blogs an applicant has written or evidence of a gambling habit or visiting hacker sites - all of which might raise a red flag. "I don't feel any restrictions going after your blog or pulling all these data together," he said.One headache at State Street is the freeware that employees download and the company wants to remove as a potential security risk. Google Desktop 3.0 search software is among the programs State Street watches out for: "It allows for file-sharing and takes the file up to the Google complex," Sweetman said."You've got to think about where that file is when Google indexes content," he said.