/usr/share/sextractor/default.conv is in sextractor 2.4.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | CONV NORM
# 3x3 ``all-ground'' convolution mask with FWHM = 2 pixels.
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2 4 2
1 2 1
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