As discussed previously, while TrickBot issues configurations (mcconf) for different campaigns (group tags) under each version number, the command and control (C2) server lists for these campaigns are usually the same for a particular version.
There have been times when multiple server lists have been seen for a particular version number of mcconf, with such occurrences having one of two explanations:
- One reason is that the distinct lists are from distinct botnets. While there is a core TrickBot botnet (iteration A through the version numbers), so far several others have been seen active for periods of time.
- However, in some cases the TrickBot operators have simply, presumably unintentionally, created discrepancies in configs - I refer to these as ‘fumbles’.
Version 1000238, from 26th July 2018 may have seen just such a fumble.
While the test ‘tt0002’ gtag for this version was distributed with a distinct C2 server list compared to 1000237 (thanks to @JR0driguez for the share), one researcher (@James_inthe_box) shared a ‘ser0726us’ gtag for version 1000238 that had a C2 server list matching that of 1000237. In contrast, two other 1000238 mcconfs shared since had the ‘tt0002’ C2 server list - and one of these was a second copy of ‘ser0726us’ (shared by @MalHunters). The other was for gtag ‘sat25’ and was shared by @James_inthe_box.
Figure 1 illustrates the differences, most notably with the additional entry present in the ‘tt0002’, second ‘ser0726us’, and ‘sat25’ gtag 1000238 configs. I’ve highlighted key entries to aid a more detailed review.
|Figure 1 - C2 Server Lists for Versions 1000237 and 1000238|
However, I shall monitor for subsequent distinct versions indicative of a new botnet.