September 04, 2012, 3:20 PM — This vendor-written tech primer has been edited by Network World to eliminate product promotion, but readers should note it will likely favor the submitters approach.
If you're charged with keeping malware out of your organization you're probably getting lots of visits from vendors of automated dynamic analysis systems for malware, the latest and greatest mouse trap being hawked by a slew of security companies.
Automated dynamic analysis systems and sandboxes for malware are the latest "must-have" antivirus gap-filler. While signature-based detection and automated static analysis systems have continued to improve in incremental jumps, and have managed to keep pace with the threats they were designed to thwart, the overall percentage of malware threats that they're capable of detecting has been decreasing for a decade.
As a detection technology, the combination of these two methods probably ends up finding 10% to 20% of malware threats within one week of the malware being created and released by the bad guys. Ten years ago, that figure was likely in the 60% to 80% range.
To address the growing detection gap, the much touted and pimped solution is to use automated dynamic analysis systems (software- or appliance-based) to uncover the maliciousness of any binary file traversing the corporate network. The idea is to force any suspicious binary to run in a mock environment so it will exhibit its true behaviors, and if those behaviors are malicious, then the file is classified as malware. To deliver this mock environment just about all the vendors hawking "better mouse trap" solutions use some form of operating system emulation or virtualization (e.g. VMware).
The objective of the approach should be to detect malware that slips by the signature and static analysis systems, taking you from 10% to 20% detection back up to the glorious days of 60% to 80%. You'll even encounter some vendors claiming their solution will take you to the oxygen-deprived altitude of 99% to 100%.
Unfortunately, the reality of the situation is considerably different from the marketing pitch. The combination of signature detection, static analysis and automated dynamic analysis systems for malware detection yields different levels of success depending on the type of threat encountered.
Consider the corporate world which faces three separate threat categories: generic Internet threats (such as any target, anywhere on the Internet, with no victim selection); infiltration threats (such as malware crafted to work against typical/average corporate defense in depth strategies); and espionage threats (such as malware tools tuned to operate within your organization).
For generic Internet threats, the combination of antivirus defenses probably thwarts 80% to 90% of threats within one week of release by criminal authors. For infiltration threats orchestrated by criminals looking for bigger monetary yields, those same defenses thwart around 40% to 50% of the malware they employ. Meanwhile, for targeted espionage threats, you'd be hard pressed to detect up to 10% of the malware tools used to conduct such an attack.
The numbers are scary - and they should be - because they reflect the reality of the situation and not some idealized marketing fluff. But context is also important here. Malware threats that come via the front door (for example over unencrypted HTTP via a Web browser, or as email attachments) are the most convenient from a threat analysis perspective and, from purely a volume perspective, you can expect 90% to 95% of those binaries to be generic Internet threats.
So, purely from a statistical basis, preventing 80% to 90% of malware coming in to your organization that way sounds great, but is that the threat you're really worried about? A piece of malware that scrapes Facebook and Twitter login credentials and will be blocked automatically by the host-based protection suite you've already deployed.
No, the threat to business lays elsewhere and the tools being positioned to fill that legacy antivirus gap have significant weaknesses.
For some reason vendors continue to tap-dance around the weaknesses of automated dynamic analysis systems, calling malware samples that evade detection as sophisticated and advanced, as if you're unlikely to ever encounter them. Sure, the technical aspects of evading sandboxing and automated analysis platforms may be specialized, but it's been largely a commodity technique for at least the last five years (just do a Google search for "malware armoring").
Today, probably about a third of all suspicious binaries traversing corporate networks that will eventually be categorized as being part of infiltration or espionage threats are VM-aware or capable of bypassing not only the current generation of automated dynamic analysis systems, but also any subsequent iteration of that technological path.
Not only are there umpteen subtle technical methods in which the malware author can detect the presence of the virtual analysis environment, but there are an almost unlimited number of unsophisticated ways to trivially achieve the same, which will be further "commoditized" to become commonplace generic Internet threats in the very near future.