I think them being Slavic speakers is in fact plausible (one element that seemed salient to me is the use of "cattle" where native speakers may perhaps have preferred "sheep" - it would work as a translation of быдло, which is a term the RUnet quite likes to apply to the sort of people they are talking about).

However, their command of English is almost certainly pretty good, seeing how they use somewhat fancy words ("closing remarks") appropriately and clearly know English idiom well ("When we feel is time to end" - using "feel" in that phrase is sufficiently peculiar to English that I wouldn't expect it from anyone who thinks in another language and translates in their head more or less mechanically). This makes it harder to rule out that the "free" file consists of exploits they collected on the market and doctored to give them a more NSAish veneer.

Another sign of Slavic speakers is the incorrect usage of "is" where "it is" would be grammatically correct.

> Q: What is in auction files? A: Is secret.

> Q: When does auction end? A: Unknown. When we feel is time to end.

A native speaker would say "it's secret" or "it's a secret", or "when we feel it's time [to end it]".

Granted, the text seems a bit like someone imitating a Russian who speaks broken English from the movies. It may well be misdirection. It's possible that non-native speakers from other languages also make this mistake, but I have seen it commonly with Slavic speakers.

(Modern) Russian doesn't even have a verb corresponding to "is", so I'm not convinced that this turn of phrase is a thing that exists outside of American movies.

I have seen actual Slavic non-native English speakers make this mistake (more than one). I haven't inquired into why. I was giving one of those people informal advice to improve their English, and that was one of the things I had to keep reminding them about.

Actors playing Russian spies in American movies sound like that, too. I don't think the README contains enough information to read into the writer's native language.

> ("When we feel is time to end" - using "feel" in that phrase is sufficiently peculiar to English that I wouldn't expect it from anyone who thinks in another language and translates in their head more or less mechanically)

This is typical of mandarin chinese; the verbs 觉得 and 感觉 are "feel" in a literal sense, but mean "think (something)".

If one language uses a metaphor, odds are some other languages do too.

Regarding the cattle remark, it might also be a reference to

> You wanted to know who I am, Zero Cool? Well, let me explain the New World Order. Governments and corporations need people like you and me. We are Samurai... the Keyboard Cowboys... and all those other people out there who have no idea what's going on are the cattle... Moooo.

That was my take as well. Writing styles are recognizable, or at least narrow-downable. Writing in that awkward style is definitely intended to neuter any style analysis.