/usr/share/sagemath/ellcurves/rank8 is in sagemath-database-elliptic-curves 0.7+dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1
457532830151317 a 1 [0,0,1,-23737,960366] 8 1