Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

ghidra: fix IndexError exception #1879

Merged
merged 4 commits into from
Dec 16, 2023
Merged

ghidra: fix IndexError exception #1879

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
3c348c6
ghidra: fix IndexError exception
mike-hunhoff Nov 29, 2023
84a6251
Update capa/features/extractors/ghidra/insn.py
mike-hunhoff Nov 29, 2023
b6f9d45
Merge branch 'master' into fix/ghidra-indexerror
colton-gabertan Dec 15, 2023
071f77e
update to match master
colton-gabertan Dec 16, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
33 changes: 19 additions & 14 deletions capa/features/extractors/ghidra/insn.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -195,20 +195,25 @@ def extract_insn_offset_features(fh: FunctionHandle, bb: BBHandle, ih: InsnHandl
if insn.getMnemonicString().startswith("LEA"):
return

# ignore any stack references
if not capa.features.extractors.ghidra.helpers.is_stack_referenced(insn):
# Ghidra stores operands in 2D arrays if they contain offsets
for i in range(insn.getNumOperands()):
if insn.getOperandType(i) == OperandType.DYNAMIC: # e.g. [esi + 4]
# manual extraction, since the default api calls only work on the 1st dimension of the array
op_objs = insn.getOpObjects(i)
if isinstance(op_objs[-1], ghidra.program.model.scalar.Scalar):
op_off = op_objs[-1].getValue()
yield Offset(op_off), ih.address
yield OperandOffset(i, op_off), ih.address
else:
yield Offset(0), ih.address
yield OperandOffset(i, 0), ih.address
if capa.features.extractors.ghidra.helpers.is_stack_referenced(insn):
# ignore stack references
return

# Ghidra stores operands in 2D arrays if they contain offsets
for i in range(insn.getNumOperands()):
mike-hunhoff marked this conversation as resolved.
Show resolved Hide resolved
if insn.getOperandType(i) == OperandType.DYNAMIC: # e.g. [esi + 4]
# manual extraction, since the default api calls only work on the 1st dimension of the array
op_objs = insn.getOpObjects(i)
if not op_objs:
colton-gabertan marked this conversation as resolved.
Show resolved Hide resolved
continue

if isinstance(op_objs[-1], ghidra.program.model.scalar.Scalar):
op_off = op_objs[-1].getValue()
else:
op_off = 0

yield Offset(op_off), ih.address
yield OperandOffset(i, op_off), ih.address


def extract_insn_bytes_features(fh: FunctionHandle, bb: BBHandle, ih: InsnHandle) -> Iterator[Tuple[Feature, Address]]:
Expand Down
17 changes: 16 additions & 1 deletion scripts/capa2yara.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,22 @@


# this have to be the internal names used by capa.py which are sometimes different to the ones written out in the rules, e.g. "2 or more" is "Some", count is Range
unsupported = ["characteristic", "mnemonic", "offset", "subscope", "Range", "os", "property", "format", "class", "operand[0].number", "operand[1].number", "substring", "arch", "namespace"]
unsupported = [
"characteristic",
"mnemonic",
"offset",
"subscope",
"Range",
"os",
"property",
"format",
"class",
"operand[0].number",
"operand[1].number",
"substring",
"arch",
"namespace",
]
# further idea: shorten this list, possible stuff:
# - 2 or more strings: e.g.
# -- https://github.com/mandiant/capa-rules/blob/master/collection/file-managers/gather-direct-ftp-information.yml
Expand Down
Loading