mkYARA

0

Free

Writing YARA rules based on executable code within malware can be a tedious task. An analyst cannot simply copy and paste raw executable code into a YARA rule, because this code contains variable values, such as memory addresses and offsets. The analyst has to disassemble the code and wildcard all the pieces in the code that can change between samples. mkYARA aims to automate this part of writing rules by generating executable code signatures that wildcard all these little pieces of executable code that are not static. Installation is as easy as installing the pip package. pip install mkyara Usage: import codecs from capstone import CS_ARCH_X86, CS_MODE_32 from mkyara import YaraGenerator gen = YaraGenerator("normal", CS_ARCH_X86, CS_MODE_32) gen.add_chunk(b"\x90\x90\x90", offset=1000) gen.add_chunk(codecs.decode("6830800000E896FEFFFFC3", "hex"), offset=0x100) gen.add_chunk(b"\x90\x90\x90\xFF\xD7", is_data=True) rule = gen.generate_rule() rule_str = rule.get_rule_string() print(rule_str) Standalone Tool: mkYARA comes with a standalone tool that is cross platform, as in, it can create signatures for Windows binaries running under Linux. Usage: mkyara [-h] [-i {x86}