Simple Settings That Could Curtail Some Attacks

Sometimes it's the little things -- a misconfigured network proxy or an unused and forgotten port -- that can make the difference in whether an organization suffers a major hack.

Organizations, especially those without the security resources to keep on top of these basic hygiene configurations, often leave themselves exposed as they struggle to keep track of the configurations. Even some large companies forget the little things or are so overwhelmed with volume that they miss them. "These little things -- not letting users download .exe files, or [not] using proxies for filtering, that don't impact the business in any way" basically raise the bar for the attacker, says Marc Maiffret, CTO and co-founder of eEye Digital Security.

So Maiffret says eEye later this week will roll out a free tool that runs a quick "health-check" on some key and simple-to-fix configuration best practices that can help shrink the attack surface. The so-called In Configuration We Trust Tool isn't meant to replace a vulnerability assessment, penetration test, or proper patch management programs, but instead to take the pulse of some of the basic protective steps in configuring a safer environment, Maiffret says.

The tool checks for 10 basic things you can do to properly configure your environment: use digitally signed running processes; use digitally signed DLLHost Services and egress port filtering; disable Microsoft Office converters; update Windows operating system with the latest releases; update Microsoft Office with the latest releases; remove administrative privileges from end user accounts; disable WebDAV; block direct downloads of executable files; and push egress traffic through a Web proxy.

The configuration best practices are based in part on findings of a report published by eEye last year that found that disabling just two well-known features in Microsoft products, WebDAV and Office file converters, would prevent attackers from exploiting 12 percent of vulnerabilities.

That set in motion an effort to zoom in on key and very simple configuration settings that can help mitigate some elements of an attack. "When you look at security, in general, and the threats affecting people on a day-to-day basis, for the most part they are preventable," Maiffret says. "A lot of people in security are looking for the quick fix -- the same as in the medical world -- a solution that will magically fix everything."

But security isn't just the tools that you put in place, but also the way you batten down the hatches and configure your environment, according to eEye. "There's always some new, major threat in the news ... Stuxnet, Aurora, NightDragon ... we're usually so fixated about the threat and what bad things it will do to the network we miss the simple dialogue: How could you actually stop this thing?" Maiffret says.

If victims of the Aurora APT attacks would have had proxy servers in place, for example, then the intellectual property thieves would not have been able to siphon data and source code, according to eEye. It wouldn't have stopped the initial infection, but it would have minimized the damage.

HD Moore, chief scientist with Rapid7 and creator of Metasploit, says organizations with limited security resources face challenges of keeping up with these types of best practices. "The lack of resources [for smaller organizations] is a real issue," Moore says. Rapid7 has free versions of its commercial penetration testing and vulnerability assessment products for small organizations "without deep pockets," he says.

eEye also already provides a free Community version of its Retina vulnerability scanner.

Rapid7's Moore says Metasploit also has some modules in the works similar to eEye's new configuration-checking tool, for testing egress filters and other configurations, for instance.

The challenge is that the bad guys are employing even more sophisticated methods that can basically get past even the best configuration practices. "Egress filtering and outbound connection monitoring does stop some of the basic malware," Moore says, "but most sophisticated agents use plain HTTP or HTTPS to make outbound connections and can easily traverse proxies."

Moore says organizations should have outbound filtering in place. "Checking for the lack of egress filtering doesn't hurt, but the malware threat has already evolved to the point that it is no longer effective on its own," he notes. And stripping end users of administrative privileges is a good practice, he says, but can also be bypassed. "[It] is often defeated by user behavior or lack of security on other local components that provide administrative access," Moore says.

[ Data suggests the focus of corporate IT on patching could cause managers to miss other important strategies to minimize risk. See The Curious Case Of Unpatchable Vulnerabilities.]

eEye's tool covers things not traditionally associated with vulnerability scanning, notes Maiffret. "It's around network-based tests like executable blocking and egress filter. These are not things you're going to discover on a specific system," he says. The tool interacts with a server eEye stood up specifically for testing outgoing and incoming traffic via the tool, he says, something vuln scanners don't do.

The tool doesn't actually fix the configuration problems it flags, but eEye also has published a new white paper that includes a how-to on fixing these common misconfigurations.

Maiffret warns that while these quick mitigation steps help, there's no guarantee a company still won't get breached. It won't be perfect, he says, but it's any easy way to reduce some attack risks.

eEye's new free tool and accompanying white paper are available for download here.

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