Repository: mandiant/capa
File: capa/ghidra/capa_explorer.py (Python)

Code before:

    rules_path: pathlib.Path = pathlib.Path(rules_dir)
    logger.info("running capa using rules from %s", str(rules_path))

    rules = capa.main.get_rules([rules_path])
    meta = capa.ghidra.helpers.collect_metadata([rules_path])
    extractor = capa.features.extractors.ghidra.extractor.GhidraFeatureExtractor()

    capabilities, counts = capa.main.find_capabilities(rules, extractor, True)

    if capa.main.has_file_limitation(rules, capabilities, is_standalone=False):
        logger.info("capa encountered warnings during analysis")

    return capa.render.json.render(meta, rules, capabilities)


def get_locations(match_dict):
    """recursively collect data from matches"""
    if "locations" in match_dict:
        for loc in match_dict.get("locations"):
            if "type" in loc:
                if loc.get("type") == "absolute" or loc.get("type") == "file":
                    yield loc.get("value"), match_dict.get("node")

    if match_dict["children"]:
        for child in match_dict.get("children"):
            yield from get_locations(child)


def parse_json(capa_data):
    """Parse json produced by capa"""
    ghidra_data = []

    rules = capa_data["rules"]
    for rule in rules.keys():
        # loosely coupled location & node data lists
        this_locs = []
        this_node: List[Dict] = []

        # dict data of currently matched rule
        this_capability = rules[rule]
        meta = this_capability["meta"]

        # return MITRE ATT&CK or None
        this_attack = meta.get("attack")

        # scope match for the rule
        this_scope = meta["scope"]
        with suppress(KeyError):
            this_locs.append(this_capability["matches"][0][0]["value"])
            # align node data

Review comment (suggestion):
```suggestion
        for child in match_dict.get("children", {}):
```

Code after:
        symbol_table = currentProgram().getSymbolTable()  # type: ignore [name-defined] # noqa: F821

        # handle function main scope of matched rule
        # these will typically contain further matches within
        if self.scope == "function":
            for addr in self.matches.keys():
                ghidra_addr = toAddr(hex(addr))  # type: ignore [name-defined] # noqa: F821

                # classify new function label under capa-generated namespace
                sym = symbol_table.getPrimarySymbol(ghidra_addr)
                if sym is not None:
                    if sym.getSymbolType() == SymbolType.FUNCTION:
                        create_label(ghidra_addr, sym.getName(), capa_namespace)
                        self.set_plate_comment(ghidra_addr)

                    # parse the corresponding nodes, and pre-comment subscope matched features
                    # under the encompassing function(s)
                    for sub_match in self.matches.get(addr):
                        for loc, node in sub_match.items():
                            sub_ghidra_addr = toAddr(hex(loc))  # type: ignore [name-defined] # noqa: F821
                            if sub_ghidra_addr == ghidra_addr:
                                # skip duplicates
                                continue

                            # precomment subscope matches under the function
                            if node != {}:
                                for sub_type, description in parse_node(node):
                                    self.set_pre_comment(sub_ghidra_addr, sub_type, description)
        else:
            # resolve the encompassing function for the capa namespace
            # of non-function scoped main matches
            for addr in self.matches.keys():
                ghidra_addr = toAddr(hex(addr))  # type: ignore [name-defined] # noqa: F821

                # basic block / insn scoped main matches
                # Ex. See "Create Process on Windows" Rule
                func = getFunctionContaining(ghidra_addr)  # type: ignore [name-defined] # noqa: F821
                if func is not None:
                    func_addr = func.getEntryPoint()
                    create_label(func_addr, func.getName(), capa_namespace)
                    self.set_plate_comment(func_addr)

                # create subscope match precomments
                for sub_match in self.matches.get(addr):
                    for loc, node in sub_match.items():
                        sub_ghidra_addr = toAddr(hex(loc))  # type: ignore [name-defined] # noqa: F821

                        if node != {}:
                            if func is not None:
                                # basic block/ insn scope under resolved function
                                for sub_type, description in parse_node(node):