According to ftp://retronn.de/archiv/old_cds/pcwelt_08_2000/pcw_mat/inhalt/PCW99.PDF page 2, this software was included on a 1999 German CD-ROM "Ausgabe 2/99" (I think that's the CD-ROM that came with the February 1999 issue of the German PC-WELT magazine), at the path "\sharewar\sw\intsich\nukefix.exe". Unfortunately I can't find an ISO of that specific CD-ROM anywhere online, but maybe someone out there has it.

what credentials work?

I've tried anon, no username/pass, etc