The Equation APT Group has been called the ultimate cyberattack tool by Kaspersky Lab researchers. The group has been linked to Stuxnet and Flame, a 15-year-old operation linked to Flame. The module has two functions: reprogramming the hard drive firmware with a custom payload; it also provides an API into hidden storage sectors of the hard drives. It’s a precious plugin that s used only in specific cases with someone very important, says Vitaly Kamluk, principal security researcher.
Source: https://threatpost.com/inside-nls_933w-dll-the-equation-apt-persistence-module/111128/