http://www.informationweek.com/news/showArticle.jhtml?articleID=193105252 By Thomas Claburn InformationWeek Oct 9, 2006 Thousands of government computers may be under the control of cybercriminals. Software bots--malicious code that turns PCs and servers into remotely controlled "zombies"--have dug into the computers of federal and state agencies, security experts say. Once infected, those computers can be used to distribute spam, launch denial-of-service attacks, and even direct sensitive information into the wrong hands. Security vendor Trend Micro, which has been studying the phenomenon and is pushing a service to detect bots, reports finding bot infestations in government computers. Its list of bot-bitten organizations includes the Department of Defense, Argonne National Laboratory, Alabama Supercomputer Network, Arkansas Department of Information Systems, Iowa Communications Network, and Connecticut's Department of IT. The Pittsburgh Supercomputing Center and Navy Network Information Center may end up on the list, too; Trend Micro last week said data pointing to bots in those two organizations was inconclusive. Trend Micro planned to disclose its findings last week--ostensibly in the interest of public awareness. But as InformationWeek followed up with organizations cited by the vendor, some of its conclusions were called into question, owing in part to the complexity of tracking these zombie computers. One national laboratory, for example, was initially identified as having compromised machines, but the lab disputed those findings, and subsequent analysis by Trend Micro revealed that the spam in question doesn't appear to come from its machines. Trend Micro has since postponed its announcement and is double-checking the 60 terabytes of data it used to do its analysis. Trend Micro attempts to identify compromised machines by analyzing spam samples received from customers of its filtering service. It's tricky work, because bot creators employ techniques to cover their tracks. "You have no idea how complex this is," says Dave Rand, Trend Micro's CTO. After initially claiming that "tens of thousands" of government computers had bots within them, Rand last week revised that tally to 7,000. That doesn't mean bots aren't a problem--they most certainly are for government agencies and businesses alike. Trend Micro estimates there are 70 million subverted computers worldwide and that 8 million to 9 million are used to send spam in a given month. Bots can remain dormant for weeks or months at a time. In general, about 60% of zombies are used to send spam and 40% for more destructive reasons, including phishing, pharming, click fraud, distributing adware or malware, denial-of-service attacks, data theft, and temporarily storing illegal, malicious, or stolen files. While most everyone agrees that the attacks are getting larger, more frequent, and more sophisticated, not everyone sees evidence that bots are a growing problem on government computers. Network security specialist Prolexic says there's been an increase in the size of distributed denial-of-service attacks, from 3.5 Gbps last year to more than 10 Gbps in 2006, yet a data sample from the company's clients doesn't show evidence of those attacks originating from government Internet addresses. That finding is based on about 40 distributed DoS attacks monitored by Prolexic in the first seven months of 2006. After being contacted by InformationWeek, Prolexic operations VP Matt Wilson did a quick search of the company's computer logs for evidence of bot attacks originating from government computers. "I didn't see anything that would have indicated mass bot infections within any government agencies or networks," he says. "That's not to say that they don't exist, simply that they aren't being used to attack our customer base." It's small comfort, however, because if government systems are being hijacked, it could be for more devious purposes. "Something like that would be much more valuable for targeted mining of things like passwords, E-mail addresses, mapping out government networks," Wilson says. Data maintained by security vendors MX Logic and IronPort confirms the presence of spam-sending bots on government networks. IronPort reports a 40% increase in spam volume since February across government and business accounts. Craig Sprosts, a senior product manager at IronPort, notes that the percentage of spam coming from government accounts is minor--1% to 2% of the overall problem--compared with what's originating from Internet service providers and other compromised networks. Not Immune Bots land on computers in a dozen ways, including operating system or application vulnerabilities, dictionary attacks that guess passwords, a pre-existing back door created by a prior computer virus, and malicious files downloaded via E-mail, instant message, or peer-to-peer applications. Bots frequently are installed as a result of human error--opening a malicious file or visiting an unsafe Web site, for example. Once installed, bots may be able to update themselves or install other malicious software. They're typically controlled though commands received from an Internet Relay Chat server, and any compromised PC can be turned into an IRC server that can then be used to coordinate a bot network. Increasingly, bots are using encrypted or covert channels of communication rather than IRC, which can easily be blocked, and they come with key-logging and screen capture capabilities, says Sam Masiello, director of threat management at MX Logic. A spokesman for the Defense Department declined to address specific security concerns, including bots, but he acknowledged that the department's computer systems are attacked daily. "The DoD aggressively responds to deter all intrusions," says Maj. Patrick Ryder via E-mail. "We're not immune, but we have a layered defense." Among the steps it takes: intrusion-detection software, firewalls, and increased awareness training of personnel. Mike Skwarek, cybersecurity program manager and deputy CIO at Argonne National Labs, hadn't seen the Trend Micro findings nor talked to the security vendor early last week as this story was being researched. But based on the description of Trend Micro's findings--that spam received from the vendor's customers points to Argonne as one source--Skwarek doesn't believe the assertions and points to spoofing as a possible explanation. "You can forge where E-mails are coming from. It's quite easy," he says. Once or twice a week, Argonne gets complaints about being a source of spam. Usually, however, its own analysis of the evidence shows that the lab wasn't at fault, that a PC suspected of sending spam was actually turned off at the time, for instance. If an Argonne PC gets infected by a bot, all E-mail is blocked from the infected PC. "We have an early warning, and that's effective," Skwarek says. Argonne has had two viruses in the past year and a half that may have been related to bots, but those viruses were quickly detected and removed. "We do a good job on the desktop fighting this," Skwarek says. While it may be tempting to discount the warnings of security vendors as self-serving--bot fever means more business for Trend Micro and others--there's unanimity about the growing risk of cybercrime. In its list of the top 10 computer security developments to watch for in 2007, released last week, the SANS Institute warns that targeted attacks will become more prevalent, particularly against government agencies. "Targeted cyberattacks by nation states against U.S. government systems over the past three years have been enormously successful, demonstrating the failure of federal cybersecurity activities," SANS director of research Alan Paller says in an E-mail. "Other antagonistic nations and terrorist groups, aware of the vulnerabilities, will radically expand the number of attacks. " Network security vendor Arbor Networks last month reported that distributed DoS attacks and botnets are the most significant security threat facing ISPs. Arbor contends that bot command-and-control networks are harder to infiltrate and that today's bots are more powerful than their ancestors, as well as more difficult to find and remove. Scott Chasin, CTO of MX Logic, concurs: "Botnets are the most dangerous enemy that the Internet has faced up until now." Wily Creatures How do government agencies and businesses protect themselves? Cigna has perimeter filtering, and PCs are regularly scanned to ensure they "stay clean," says chief information security officer Craig Shumard. The health insurer looks for signatures that indicate bot activity. Protecting against denial-of-service attacks is a concern, too, so Cigna is strict about employees who telecommute. For instance, telecommuters can use only company-issued PCs to access Cigna sys- tems. And company PCs are regularly updated with antivirus and other security software. Like Shumard, Bob Pappagianopoulos, chief information security officer with Partners HealthCare System, says bots aren't a problem at his organization. Pappagianopoulos got an update last week from staffers responsible for monitoring, scanning, and detecting security problems. "We haven't seen a gross influx of bots," he says. Yet he admits that cybercriminals "are getting smarter in hiding their trail." One of the most effective defenses against bots is to take administrative access away from PC users, says Tom Olzak, IT security director for HCR Manor Care, a $3 billion-a-year operator of nursing homes in 32 states. But bots are wily, as are the people who create and control them. Bots can be used to quietly gather information that attackers can later use to extort a company through threat of distributed DoS attacks that make their networks and systems unusable. "The sky's the limit in terms of what they can do," Olzak says. When installed as rootkits, bots are difficult to detect and remove, so it's important to have systems for network intrusion detection and prevention, in addition to PC security software. The key is to "detect, identify, isolate, and stop" bots quickly before they do damage or infect other systems, says Jim Mazzonna, chief of the Info Assurance Division of the U.S. Coast Guard's Telecommunication & Information Systems Command. "Are we seeing more bots? Yes. But we have sensors all over the place, and we can detect and isolate them quickly," he says. The U.S. Navy's Cyber Defense Operations Center uses intrusion detection and prevention systems as part of a sensor grid to monitor and protect Naval computers. In most cases, bot activity can be identified and shut down automatically by these systems, according to the Navy. However, the Navy acknowledges that the approach isn't foolproof. "From time to time we get reports from other organizations that have visibility into networks that we may not have sensors on," according to a written statement provided by a Navy spokesman. "Once we get the report, we can take appropriate action to get the network secured." The Navy neither confirmed nor denied Trend Micro's report of bots on some of its computers. Early Warning Security researchers and vendors have been warning about bots for years. In his 2005 paper "Bots And Botnets: Risks, Issues And Prevention," Martin Overton, a security researcher with IBM Global Services, asserted that IT professionals had only a vague understanding of the threat posed by bots and botnets. "In many institutions and corporations, bots and botnets are rife and causing significant damage to the infected network owner," through lost bandwidth, intellectual property, and reputation, Overton wrote. The culprits don't always get away with it. In August, 21-year-old Christopher Maxwell of Vacaville, Calif., was sentenced to 37 months in prison and three years of supervised release for operating an IRC botnet that compromised millions of computers, including some operated by the Department of Defense. A Defense Department investigation determined Maxwell was responsible for computer intrusions at military installations worldwide, resulting in repair costs of at least $172,000. In January, 20-year-old Jeanson James Ancheta pleaded guilty to violating the Computer Fraud Abuse Act and damaging federal computers. He admitted to generating some $60,000 in advertising proceeds by directing more than 400,000 infected computers that were part of a botnet army to servers he controlled, from which he would surreptitiously download adware onto the zombies, according to the FBI. The Federal Trade Commission last year launched Operation Spam Zombies, a campaign to encourage ISPs to take steps to defend their networks from misuse. "Your organization has an interest in the integrity of the E-mail system, which is threatened by the onslaught of spam routed through spam zombies," the FTC said in its call for action. The FTC, however, can't say whether its campaign has been effective. Trend Micro's Rand recalls uncovering a bot infestation at a network operator in France that involved a half-million infected computers. At the rate that the network operator is moving, he says, it will take 271 years to get the bots off all of its computers. "We in the security industry have done a really crappy job of giving the ISP and IT community the right set of tools to address this problem," he says. Symantec, in its Internet Security Threat Report for the first six months of 2006, isn't as alarmed, speculating that the bot population has "reached the saturation point." But the report also states that bot network owners are being more discreet about their activities to avoid law enforcement. Symantec finds that 2.91% of all PCs in Beijing have been compromised by bots, the highest percentage of any city worldwide. The U.S. cities with the greatest bot infections are Los Angeles, where an estimated 1.2% of all PCs are zombies, and Chicago, at 0.99%. The sheer numbers are hard to pin down. Trend Micro claims that it once shut down a botnet that had 1.25 million computers attached to it. Cybercriminals are less likely to cast such a wide net today. "We don't see that anymore," Rand says. "We don't see huge volumes of machines under one command-and-control site. They're well dispersed." Detection Is Difficult That's what's new here: The crooks are adapting to avoid detection. They've designed their botnets to minimize disruption when one bot gets taken down. They're writing exploit code aimed at specific networks, which makes detection much more difficult. Security vendors may never even see limited-distribution exploit code, and if they do, it may not be worth adding it to their pattern files because the exploit affects only a few hundred or thousand machines. What's more, attacks are becoming more sophisticated and automated. The vast computational power of Google, the product of hundreds of thousands of servers, is often cited as a benchmark for distributed supercomputing. The reality is that cybercriminals could effectively run the world's most powerful supercomputer, making it trivial to conduct computationally intensive operations like generating millions of unique image spam files to evade filters or unleashing massive malware attacks. Rand cites the MS06-040 Microsoft vulnerability, disclosed on Aug. 8, which changed the infection rate of PCs from about a quarter of a million new machines per month to a quarter of a million new machines per day in the first few days. "Those numbers are staggering," he says. "When you start to put that together with other technologies, these people have enormous, enormous computing power at their disposal." Given their middleman role on the Internet, ISPs are in a position to help stop bots, but Rand and others say they aren't doing enough. Fact is, ISPs can make more money ignoring cybercrime than fighting it. "Their feeling is, 'Hey, it's not our problem if the user is an idiot.' And my response to that is, you can't expect my mother to be responsible for Windows XP security. Sorry, you need to take a more active role." Richi Jennings, an analyst with messaging research firm Ferris Research, recommends that ISPs disconnect zombie PCs from the Internet until they or the user can remove the malicious software. Is that even possible? On a small scale it is. Lariat.net, a wireless ISP serving Laramie, Wyo., offers to install freely available security software for its users. "We scan every one of their machines before we grant them network access," says Lariat owner Brett Glass. "We're not typical." Even so, Lariat's users may end up with compromised machines. A recent round of zero-day attacks turned some machines into spam bots. But thanks to traffic monitoring, Lariat was able to identify subverted machines and fix them. "We keep the best handle on it we can," Glass says. "But most Internet users who go to the store and buy a computer are sitting ducks. If they use the computer as configured and as directed, the odds are overwhelming that they'll be infected within a few hours." Fight Back Telecom carrier BellSouth can't say whether bots are any worse today than in the past, but there's no doubt they're an issue. In the fourth quarter, BellSouth will start using "an industry best solution" that's in beta testing now to better understand its network usage so that it can target malicious software, says Michael Spoor, director of network infrastructure and security at BellSouth. The company's multilayered strategy for fighting bots includes encouraging its customers to "self-protect" home PCs, including downloading a security software suite BellSouth makes available on its site or from another source. "BellSouth looks to its customers to help us help them," Spoor says. Every day, BellSouth blocks millions of suspected spam messages from crossing its network, he says. Teams within BellSouth work on the problem of spam, bots, and viruses. Ken Kousky, CEO of security market research firm IP3, argues that law enforcement needs to do more, too. He contends that U.S. authorities have been less than enthusiastic in their efforts to protect the porn and gambling businesses that are often threatened by criminals armed with botnets. "We've tried to find a case where law enforcement has taken a proactive effort to defend a porn site and, as far as I know, there are no instances of this," he says. "The challenge in botnets is to stop the flow of funds." New technologies promise some relief. Trend Micro recently announced its InterCloud Security Service specifically for bot detection; IronPort sells its C10 E-mail appliance and virus outbreak filters; MX Logic this week plans to introduce a Web Defense Service to protect small and midsize businesses from malware; and Symantec and Panda Software recently released updated Internet security software packages. But these are temporary fixes at best. Malware writers are adept at countering the countermeasures. To complicate matters, it's hard to change human nature. "The stuff we're talking about in general is caused by human error," says the SANS Institute's Paller. "The government has done essentially nothing to illuminate human error and get rid of it. The awareness training that goes on in the federal government--except at the U.S. Agency for International Development--is pretty much useless." Not so at West Point. Computer security training, which has been part of the curriculum for six years, was the subject of a series of exercises called Carronade that ran between early 2004 and late 2005, testing the susceptibility of E-mail users to both general and targeted phishing attacks. The rate at which students fell for phishing attacks dropped from more than 50% among freshmen to less than 20% for seniors, says Lt. Col. Ronald C. Dodge Jr., associate professor in the academy's department of electrical engineering and computer science. There's still room for improvement. In a paper detailing the West Point study, "Phishing For User Security Awareness," Dodge and co-authors Curtis Carver and Aaron Ferguson conclude, "Our students continue to disclose information that should not be disclosed to an unauthorized user and expose themselves to malicious code by opening attachments." Paller gives the U.S. Agency for International Development high marks because it forces security training on its PC users every day as part of the logon process. Ultimately, that kind of intrusive, unavoidable insistence on security may be necessary to help bot-fighting technology do its job. Copyright 2005 CMP Media LLC _________________________________ Visit the InfoSec News store! http://www.shopinfosecnews.org
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