[...] Did anybody search for the system “about 15 ly back” according to the log where it was supposedly infected by a killer computer virus. [...]
If I remember correctly there were a lot of CMDRs searching for hints, backstory and so on almost two years ago when the Thetis and the other generation ships were found.
And there were a lot of threads with this topic, I've bookmarked only two of them:
The (no longer) Missing - Rediscovered Generation Ships
Generation Ship Thetis found
Don't have enough time to dig through them. Maybe you can find something.