I was just wondering if it's in the same directory, maybe the permissions are not sufficient, and you should source the file?
#!/usr/bin/perl
use strict;
use warnings;
print system (qw/.\/runssh_bro.pl 10.77.77.77 filename1.out/);
print system (qw/.\/runssh_bro.pl 10.77.77.77 filename2.out/);