Updated 02-23-2005  Security Risk: *****

Microsoft Warns of New Security Threat

System monitoring programs, called rootkits, may pose a serious danger to your PC. Paul Roberts, IDG News Service/Pcworld.com Thursday, February 17, 2005 Microsoft security researchers are warning about a new generation of powerful system monitoring programs, or "rootkits," that are almost impossible to detect using current security products and that could pose a serious risk to corporations and individuals.

The researchers discussed the growing threat posed by kernel root kits at a session at the RSA Security Conference in San Francisco this week. The malicious snooping programs are becoming more common and could soon be used to create a new generation of mass-distributed spyware and worms.

With names like "Hacker Defender," "FU," and "Vanquish," the programs are the latest generation of remote system monitoring software that has been around for years, according to Mike Danseglio and Kurt Dillard, both of Microsoft's Security Solutions Group.

The programs are used by malicious hackers to control, attack, or ferret information from systems on which the software has been installed and are typically installed on a machine without the owner's knowledge, either by a virus or following a successful hack of the computer's defenses, they say.

Running in the Background Once installed, many rootkits simply run quietly in the background but can easily be spotted by looking for memory processes that are running on the infected system, monitoring outbound communications from the machine, or checking for newly installed programs.

However, kernel rootkits, which modify the kernel, or core request processing, component of an operating system, are becoming more common. Rootkit authors are also making huge strides in their ability to hide their creations, says Danseglio.

In particular, some newer rootkits are able to intercept queries or "system calls" that are passed to the kernel and filter out queries generated by the rootkit software. The result is that typical signs that a program is running, such as an executable file name, a named process that uses some of the computer's memory, or configuration settings in the operating system's registry, are invisible to administrators and to detection tools, says Danseglio.

The increasingly sophisticated rootkits and the speed with which techniques are migrating from rootkits to spyware and viruses may be the result of influence from organized online criminal groups that value stealthy, invasive software, says Dillard.

One rootkit, called Hacker Defender, which was released about one year ago, even uses encryption to protect outbound communications and can piggyback on commonly used ports such as TCP (Transmission Control Protocol) port 135 to communicate with the outside world without interrupting other applications that communicate on that port, he says.

Detection Options The kernel rootkits are invisible to many detection tools, including antivirus, host, and network intrusion detection sensors (IDS) and anti-spyware products, the researchers say.

In fact, some of the most powerful tools for detecting the rootkits are designed by rootkit authors, not security companies, they say.

There are few strategies for detecting kernel rootkits from an infected system, especially because each rootkit behaves differently and uses different strategies to hide itself.

It is sometimes possible to spot kernel rootkits by examining infected systems from another machine on a network, says Dillard. Another strategy to spot kernel rootkits is to use Windows PE, a stripped-down version of the Windows XP operating system that can be run from a CD-ROM, to boot a computer, then comparing the profile of the clean operating system to the infected system, according to Dillard and Danseglio.

Microsoft researchers have even developed a tool, named "Strider Ghostbuster" that can detect rootkits by comparing clean and suspect versions of Windows and looking for differences that may indicate a kernel rootkit is running, according to a paper published by Microsoft Research.

Still, the only reliable way to remove kernel rootkits is to completely erase an infected hard drive and reinstall the operating system from scratch, Danseglio says.

Although rootkits are not unique to Windows, the popular operating system is a rich target and makes it easy for malicious hackers to disguise the presence of such programs, according to Jonathan Levin, of Symantec's @stake division who attended the presentation at RSA.

The operating system's powerful APIs (application programming interfaces) make it easy to mask behaviors on the system. The company's popular Internet Explorer Web browser is also a frequent avenue for malicious hackers, viruses, and worms that could drop a rootkit on a vulnerable Windows system, Levin says.

Better tools could be built to detect the current crop of kernel rootkits. However, rootkit authors are adept at spotting new detection techniques and modifying their programs to slip around them, Danseglio says.

"These people are smart. They're very smart," he says.

FBI Issues Warning About Computer Virus 2/23/2005

WASHINGTON (AP) - The FBI warned Tuesday that a computer virus is being spread through unsolicited e-mails that purport to come from the FBI.

The e-mails appear to come from an fbi.gov address. They tell recipients that they have accessed illegal Web sites and that their Internet use has been monitored by the FBI's "Internet Fraud Complaint Center," the FBI said.

The messages then direct recipients to open an attachment and answer questions. The computer virus is in the attachment.

"Recipients of this or similar solicitations should know that the FBI does not engage in the practice of sending unsolicited e-mails to the public in this manner," the FBI said in a statement.

The bureau is investigating the phony e-mails.

The agency earlier this month shut down fbi.gov accounts, used to communicate with the public, because of a security breach. A spokeswoman said the two incidents appear to be unrelated