a-ray-grass is a YARA module that provides support for DCSO format bloom filters in YARA. In the context of hashlookup, it allows quickly discard known files 'pour séparer le grain de l'ivraie'. Installation: - Copy the folder libyara/fleur in libyara - Copy the folder libyara/modules/araygrass in libyara/modules - Modify libyara/Makefile.am - Add modules/araygrass/araygrass.c to the MODULES variable - Add fleur/fnv.c and fleur/fleur.c to the libyara_la_SOURCES variable - Modify /libyara/modules/module_list - Append MODULE(araygrass) at the end of the file - Finally modify libyara/modules/araygrass/araygrass.c There you will find two paths defined: - BF_PATH_IN: specify here the path to your input bloom filter, the filter against which variables will be checked - BF_PATH_OUT: specify here the path where you wish to save the modified bloom filter after YARA finished its execution. It can be left empty if no modifications are made to the filter. It's totally ok to set the same path for both variables. Compilation: - Go back to YARA's root folder and make