# This file is Copyright 2019 Volatility Foundation and licensed under the Volatility Software License 1.0
# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
#
import logging
from typing import Iterable, List, Tuple
import datetime
from volatility3.framework import interfaces, renderers
from volatility3.framework.configuration import requirements
from volatility3.framework.renderers import format_hints
from volatility3.plugins import yarascan
from volatility3.plugins.windows import pslist
vollog = logging.getLogger(__name__)
[docs]
class VadYaraScan(interfaces.plugins.PluginInterface):
"""Scans all the Virtual Address Descriptor memory maps using yara."""
_required_framework_version = (2, 22, 0)
_version = (1, 1, 4)
[docs]
@classmethod
def get_requirements(cls) -> List[interfaces.configuration.RequirementInterface]:
# create a list of requirements for vadyarascan
vadyarascan_requirements = [
requirements.ModuleRequirement(
name="kernel",
description="Windows kernel",
architectures=["Intel32", "Intel64"],
),
requirements.VersionRequirement(
name="pslist", component=pslist.PsList, version=(3, 0, 0)
),
requirements.VersionRequirement(
name="yarascanner", component=yarascan.YaraScanner, version=(2, 0, 0)
),
requirements.VersionRequirement(
name="yarascan", component=yarascan.YaraScan, version=(2, 0, 0)
),
requirements.ListRequirement(
name="pid",
element_type=int,
description="Process IDs to include (all other processes are excluded)",
optional=True,
),
]
# get base yarascan requirements for command line options
yarascan_requirements = yarascan.YaraScan.get_yarascan_option_requirements()
# return the combined requirements
return yarascan_requirements + vadyarascan_requirements
def _generator(self):
rules = yarascan.YaraScan.process_yara_options(dict(self.config))
filter_func = pslist.PsList.create_pid_filter(self.config.get("pid", None))
sanity_check = 1024 * 1024 * 1024 # 1 GB
for task in pslist.PsList.list_processes(
context=self.context,
kernel_module_name=self.config["kernel"],
filter_func=filter_func,
):
layer_name = task.add_process_layer()
layer = self.context.layers[layer_name]
max_vad_size = 0
vad_maps_to_scan = []
for start, size in self.get_vad_maps(task):
if size > sanity_check:
vollog.debug(
f"VAD at 0x{start:x} over sanity-check size, not scanning"
)
continue
max_vad_size = max(max_vad_size, size)
vad_maps_to_scan.append((start, size))
if not vad_maps_to_scan:
vollog.warning(
f"No VADs were found for task {task.UniqueProcessId}, not scanning"
)
continue
scanner = yarascan.YaraScanner(rules=rules)
scanner.chunk_size = max_vad_size
# scan the VAD data (in one contiguous block) with the yarascanner
for start, size in vad_maps_to_scan:
for offset, rule_name, name, value in scanner(
layer.read(start, size, pad=True), start
):
layer_data = renderers.LayerData(
context=self.context,
offset=offset,
layer_name=layer.name,
length=len(value),
)
yield (
0,
(
format_hints.Hex(offset),
task.UniqueProcessId,
task.get_create_time(),
task.InheritedFromUniqueProcessId,
task.ImageFileName.cast(
"string",
max_length=task.ImageFileName.vol.count,
errors="replace",
),
task.get_session_id(),
task.ActiveThreads,
rule_name,
name,
layer_data,
),
)
[docs]
@classmethod
def get_vad_maps(
cls,
task: interfaces.objects.ObjectInterface,
) -> Iterable[Tuple[int, int]]:
"""Creates a map of start/end addresses within a virtual address
descriptor tree.
Args:
task: The EPROCESS object of which to traverse the vad tree
Returns:
An iterable of tuples containing start and size for each descriptor
"""
vad_root = task.get_vad_root()
for vad in vad_root.traverse():
yield (vad.get_start(), vad.get_size())
[docs]
def run(self):
return renderers.TreeGrid(
[
("Offset", format_hints.Hex),
("PID", int),
("CreateTime", datetime.datetime),
("PPID", int),
("ImageFileName", str),
("SessionId", int),
("Threads", int),
("Rule", str),
("Component", str),
("Value", renderers.LayerData),
],
self._generator(),
)