The Department of Commerce agency, which is tasked with developing standards and recommendations including in the area of IT security, has published a guide to application whitelisting that explains the technology in detail and offers practical advice for how it should be used.
For one, before looking at third-party products, organizations should consider using the application whitelisting mechanisms included in the operating systems they use on their desktops, laptops and servers. The reason is that they're easier to use, can be centrally managed and their use keeps additional costs minimal.
Another important aspect is to use whitelisting mechanisms that can identify applications by more attributes than path, file name, and size.
"A combination of digital signature/publisher and cryptographic hash techniques generally provides the most accurate and comprehensive application whitelisting capability," NIST said in its guide.
Antivirus and many other security technologies use a blacklist approach. They detect and block malicious programs based on code signatures, behavioral traits, indicators of compromise and other attributes.
However, this approach is prone to frequent failure, as attackers can modify their malware to evade detection, especially if they know which security product their target uses, and can also generate false positives -- the blocking of legitimate apps.
By comparison, application whitelisting and control technologies only allow pre-approved programs and services to run, and block everything else. The trick, however, is to close all ways in which malicious applications could masquerade as legitimate ones.
Companies looking to deploy application whitelisting should do so in stages, in order to identify problems early and minimize their impact. Before deployment, it's recommended to thoroughly test the technology in monitoring mode and determine how it deals with potential changes to pre-approved applications, such as those caused by software updates, NIST said.
"Organizations considering application whitelisting deployment in a typical managed environment should perform a risk assessment to determine whether the security benefits provided by application whitelisting outweigh its possible negative impact on operations," NIST said.
Companies should also understand that managing this kind of technology will require dedicated staff in the same way antivirus or intrustion detection products do, the agency said.