Sofacy, also known as APT28, Fancy Bear, and Tsar Team, is a prolific, well resourced, and persistent adversary. They are sometimes portrayed as wild and reckless, but as seen under our visibility, the group can be pragmatic, measured, and agile. Our previous post on their 2017 activity stepped away from the previously covered headline buzz presenting their association with previously known political hacks and interest in Europe and the US, and examines their under-reported ongoing activity in middle east, central asia, and now a shift in targeting further east, including China, along with an overlap surprise. There is much understated activity that can be clustered within this set and overlap in APT activity. Here, we examine current deployment, code, cryptography, and targeting.
Essentially, this examination finds the group maintains subdivisions of efforts in targeting, development, and coding. Comparisons to other modules quickly shows a delineation in other Sofacy efforts. SPLM, GAMEFISH, and Zebrocy delivery all maintain their own clusters, but frequently overlap later.
Because SPLM is their primary and selective second stage tool, SPLM deployment is of much interest. But Zebrocy efforts are in such high volume, that these modules need examination as well.
SPLM, otherwise known as CHOPSTICK, or by the author(s) as “XAgent”, is described as Sofacy’s signature second stage tool, selectively used for years against around the world. Really, many modified XAgent modules have been deployed over the years. Even the individual Linux modules renamed as “Fysbis” backdoors released in 2016 were merely modified and reduced portions of recompiled XAgent C/C++ codebase. Anyway, SPLM/CHOPSTICK has maintained various combinations of code, with some recognizable functionality listed here.