A question of ngs_mapper2 output file abount malformed.bed

[craftor18]

Hi, I get a sample output for ngs_mapper2 method,and its ouput has a malformed.bed ,what does it means?

total 4.2M
-rw-rw-r-- 1 zengy zengy 7.9K Jun  3 07:23 hc7_ngs_te_mapper2_malformed.bed
-rw-rw-r-- 1 zengy zengy 1.8M Jun  3 07:23 hc7_ngs_te_mapper2_redundant.bed
drwxrwxr-x 3 zengy zengy 4.0K Jun  3 07:23 ./
-rw-rw-r-- 1 zengy zengy 746K Jun  3 07:23 hc7_ngs_te_mapper2_nonredundant_non-reference_siteonly.vcf
-rw-rw-r-- 1 zengy zengy 1.8M Jun  3 07:23 hc7_ngs_te_mapper2_nonredundant.bed
drwxrwxr-x 4 zengy zengy 4.0K Jun  3 07:23 ../
drwxrwxr-x 2 zengy zengy 4.0K Jun  4 11:35 unfiltered/

like this above ,can I have a answer about it means?
Thank you so much,Best Wishes!