ghidra: fix lints

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -34,6 +34,7 @@
 ### Bug Fixes
 
 - binja: fix a crash during feature extraction when the MLIL is unavailable @xusheng6 #2714 
+- embedded pe: use FileOffset rather than AbsoluteVirtualAddress for IDA, Ghidra, and Binary Ninja @williballenthin #2745 
 
 ### capa Explorer Web
 

capa/features/extractors/binja/file.py

@@ -32,7 +32,7 @@ from capa.features.common import (
     Characteristic,
 )
 from capa.features.address import NO_ADDRESS, Address, FileOffsetAddress, AbsoluteVirtualAddress
-from capa.features.extractors.binja.helpers import read_c_string, unmangle_c_name
+from capa.features.extractors.binja.helpers import read_c_string, unmangle_c_name, va_to_file_offset
 
 
 def check_segment_for_pe(bv: BinaryView, seg: Segment) -> Iterator[tuple[Feature, Address]]:
@@ -46,7 +46,8 @@ def check_segment_for_pe(bv: BinaryView, seg: Segment) -> Iterator[tuple[Feature
     buf = bv.read(seg.start, seg.length)
 
     for offset, _ in capa.features.extractors.helpers.carve_pe(buf, start):
-        yield Characteristic("embedded pe"), FileOffsetAddress(seg.start + offset)
+        file_off = va_to_file_offset(bv, seg.start + offset)
+        yield Characteristic("embedded pe"), FileOffsetAddress(file_off)
 
 
 def extract_file_embedded_pe(bv: BinaryView) -> Iterator[tuple[Feature, Address]]:
@@ -122,7 +123,8 @@ def extract_file_section_names(bv: BinaryView) -> Iterator[tuple[Feature, Addres
 def extract_file_strings(bv: BinaryView) -> Iterator[tuple[Feature, Address]]:
     """extract ASCII and UTF-16 LE strings"""
     for s in bv.strings:
-        yield String(s.value), FileOffsetAddress(s.start)
+        file_off = va_to_file_offset(bv, s.start)
+        yield String(s.value), FileOffsetAddress(file_off)
 
 
 def extract_file_function_names(bv: BinaryView) -> Iterator[tuple[Feature, Address]]:

capa/features/extractors/binja/helpers.py

@@ -84,3 +84,29 @@ def get_llil_instr_at_addr(bv: BinaryView, addr: int) -> Optional[LowLevelILInst
     if arch.get_instruction_low_level_il(buffer, addr, llil) == 0:
         return None
     return llil[0]
+
+
+def va_to_file_offset(bv: BinaryView, va: int) -> int:
+    """Map a BinaryView virtual address to a file offset using segment/section data offsets.
+
+    Assumes a modern Binary Ninja API where Segment and Section objects expose
+    a `data_offset` attribute which is the file offset of the start of the
+    segment/section. The file offset is computed as:
+
+        file_offset = segment.data_offset + (va - segment.start)
+
+    If no containing segment/section is found, fall back to returning the
+    given virtual address as an integer.
+    """
+    # prefer segments (they map ranges of the file view)
+    for seg in bv.segments:
+        if seg.start <= va < seg.start + seg.length:
+            return int(seg.data_offset + (va - seg.start))
+
+    # otherwise check sections
+    for _, sec in bv.sections.items():
+        if sec.start <= va < sec.start + sec.length:
+            return int(sec.data_offset + (va - sec.start))
+
+    # fallback
+    return int(va)

capa/features/extractors/ghidra/file.py

@@ -85,10 +85,11 @@ def extract_file_embedded_pe() -> Iterator[tuple[Feature, Address]]:
             continue
 
         for off, _ in find_embedded_pe(capa.features.extractors.ghidra.helpers.get_block_bytes(block), mz_xor):
-            # add offset back to block start
-            ea: int = block.getStart().add(off).getOffset()
+            # add offset back to block start (Address)
+            addr = block.getStart().add(off)
+            off_file = capa.features.extractors.ghidra.helpers.addr_to_file_offset(addr)
 
-            yield Characteristic("embedded pe"), FileOffsetAddress(ea)
+            yield Characteristic("embedded pe"), FileOffsetAddress(int(off_file))
 
 
 def extract_file_export_names() -> Iterator[tuple[Feature, Address]]:
@@ -140,12 +141,14 @@ def extract_file_strings() -> Iterator[tuple[Feature, Address]]:
         p_bytes = capa.features.extractors.ghidra.helpers.get_block_bytes(block)
 
         for s in capa.features.extractors.strings.extract_ascii_strings(p_bytes):
-            offset = block.getStart().getOffset() + s.offset
-            yield String(s.s), FileOffsetAddress(offset)
+            addr = block.getStart().add(s.offset)
+            offset = capa.features.extractors.ghidra.helpers.addr_to_file_offset(addr)
+            yield String(s.s), FileOffsetAddress(int(offset))
 
         for s in capa.features.extractors.strings.extract_unicode_strings(p_bytes):
-            offset = block.getStart().getOffset() + s.offset
-            yield String(s.s), FileOffsetAddress(offset)
+            addr = block.getStart().add(s.offset)
+            offset = capa.features.extractors.ghidra.helpers.addr_to_file_offset(addr)
+            yield String(s.s), FileOffsetAddress(int(offset))
 
 
 def extract_file_function_names() -> Iterator[tuple[Feature, Address]]:

capa/features/extractors/ghidra/helpers.py

@@ -306,3 +306,31 @@ def find_data_references_from_insn(insn, max_depth: int = 10):
                 break
 
         yield to_addr
+
+
+def addr_to_file_offset(addr: ghidra.program.model.address.Address) -> int:
+    """Map a Ghidra Address to a file offset using section information.
+
+    Assumes a modern Ghidra version where MemoryBlock provides
+    `getStartingOffset()` and `getStart()/getEnd()` are available.
+
+    Algorithm:
+      - iterate memory blocks, find the block containing `addr`
+      - compute section-relative offset = addr - block.start
+      - compute file offset = block.getStartingOffset() + section-relative offset
+      - if no block matches, fall back to subtracting program image base
+    """
+    prog = currentProgram()  # type: ignore[name-defined] # noqa: F821
+    aoff = addr.getOffset()
+
+    for block in prog.getMemory().getBlocks():  # type: ignore[name-defined] # noqa: F821
+        bstart = block.getStart().getOffset()
+        bend = block.getEnd().getOffset()
+        if bstart <= aoff <= bend:
+            sec_rel = aoff - bstart
+            file_base = block.getStartingOffset()
+            return int(file_base + sec_rel)
+
+    # if no block matched, fall back to image-base subtraction
+    base = prog.getImageBase().getOffset()
+    return int(aoff - base)

capa/features/extractors/ida/file.py

@@ -20,6 +20,7 @@ import idc
 import idaapi
 import idautils
 import ida_entry
+import ida_loader
 
 import capa.ida.helpers
 import capa.features.extractors.common
@@ -87,7 +88,8 @@ def extract_file_embedded_pe() -> Iterator[tuple[Feature, Address]]:
     """
     for seg in capa.features.extractors.ida.helpers.get_segments(skip_header_segments=True):
         for ea, _ in check_segment_for_pe(seg):
-            yield Characteristic("embedded pe"), FileOffsetAddress(ea)
+            off = ida_loader.get_fileregion_offset(ea)
+            yield Characteristic("embedded pe"), FileOffsetAddress(off)
 
 
 def extract_file_export_names() -> Iterator[tuple[Feature, Address]]:
@@ -161,10 +163,12 @@ def extract_file_strings() -> Iterator[tuple[Feature, Address]]:
 
         # differing to common string extractor factor in segment offset here
         for s in capa.features.extractors.strings.extract_ascii_strings(seg_buff):
-            yield String(s.s), FileOffsetAddress(seg.start_ea + s.offset)
+            off = ida_loader.get_fileregion_offset(seg.start_ea + s.offset)
+            yield String(s.s), FileOffsetAddress(off)
 
         for s in capa.features.extractors.strings.extract_unicode_strings(seg_buff):
-            yield String(s.s), FileOffsetAddress(seg.start_ea + s.offset)
+            off = ida_loader.get_fileregion_offset(seg.start_ea + s.offset)
+            yield String(s.s), FileOffsetAddress(off)
 
 
 def extract_file_function_names() -> Iterator[tuple[Feature, Address]]: