/usr/lib/python2.7/dist-packages/rekall/plugins/windows/kernel.py is in python-rekall-core 1.6.0+dfsg-2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | #!/usr/bin/python
# Rekall Memory Forensics
# Copyright (C) 2014 Michael Cohen <scudette@gmail.com>
# Copyright 2014 Google Inc. All Rights Reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or (at
# your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
"""This module discovers the kernel base address.
The profile provides kernel addresses relative to the kernel base address. This
varies each time, so we need a way to locate the kernel base address in the
kernel address space.
"""
__author__ = "Michael Cohen <scudette@google.com>"
from rekall import obj
from rekall import scan
from rekall.plugins import core
from rekall.plugins.windows import common
from rekall.plugins.overlays.windows import pe_vtypes
class ExportScanner(scan.BaseScanner):
# We search for the name of a section present in the PE header.
checks = [("MultiStringFinderCheck", dict(needles=[
"INITKDBG", "MISYSPTE", "PAGEKD"]))]
class ObjectTreeHook(common.AbstractWindowsParameterHook):
"""Cache the object tree."""
name = "object_tree"
def BuildTree(self, result, root, seen):
for x in root:
# This prevents circular references to parent objects. They should
# never happen but some possibly corrupt images may contain links to
# parent objects.
if x.obj_offset in seen:
continue
seen.add(x.obj_offset)
name = x.NameInfo.Name.v()
if name == None:
continue
# We store the _OBJECT_HEADER offset and some metadata about the
# types.
object_type = x.get_object_type()
entry = result[name] = dict(
type=object_type,
type_name="_OBJECT_HEADER",
offset=x.obj_offset,
)
if object_type == "Directory":
children = entry["Children"] = {}
self.BuildTree(children, x.Object, seen)
@core.MethodWithAddressSpace()
def calculate(self):
seen = set()
root = self.session.profile.get_constant_object(
"ObpRootDirectoryObject",
target="Pointer",
target_args=dict(
target="_OBJECT_DIRECTORY"
)
)
result = dict(
type="Directory",
type_name="_OBJECT_DIRECTORY",
offset=root.deref().obj_offset,
Children={})
self.BuildTree(result["Children"], root, seen)
return result
class DriveLetterDeviceHook(common.AbstractWindowsParameterHook):
"""Maps device names to drive letters."""
name = "drive_letter_device_map"
@core.MethodWithAddressSpace()
def calculate(self):
try:
result = {}
obj_tree_plugin = self.session.plugins.object_tree()
# The global path contains symlinks from the drive letter to the
# device name.
for global_obj in obj_tree_plugin.GetObjectByName(
r"\GLOBAL??").Object:
name = global_obj.NameInfo.Name.v()
if (global_obj.get_object_type() == "SymbolicLink" and
len(name) > 1 and name[1] == ":"):
target = global_obj.Object.LinkTarget.v()
result[target] = name
return result
# If we fail to traverse the object tree we just return None which will
# fail to resolve this drive letter but will try again next time.
except KeyError:
return None
class KernelBaseHook(common.AbstractWindowsParameterHook):
"""Finds the kernel base address."""
name = "kernel_base"
def calculate(self):
address_space = self.session.kernel_address_space
if not address_space:
return
scanner = ExportScanner(session=self.session,
address_space=address_space)
# The kernel image is always loaded in the same range called the
# "Initial Loader Mappings". Narrowing the possible range makes scanning
# much faster. (See http://www.codemachine.com/article_x64kvas.html)
if self.session.profile.metadata("arch") == "AMD64":
kernel_boundary = 0xFFFFF80000000000
else:
kernel_boundary = 0x80000000
maxlen = 0xFFFFF87FFFFFFFFF - kernel_boundary
kernel_boundary = obj.Pointer.integer_to_address(kernel_boundary)
for hit in scanner.scan(offset=kernel_boundary, maxlen=maxlen):
# Search backwards for an MZ signature on the page boundary.
page = hit & 0xFFFFFFFFFFFFF000
for _ in range(10):
if address_space.read(page, 2) == "MZ":
helper = pe_vtypes.PE(
address_space=address_space,
session=self.session, image_base=page)
if str(helper.RSDS.Filename) in common.KERNEL_NAMES:
self.session.logging.info(
"Detected kernel base at 0x%X", page)
return page
else:
page -= 0x1000
class WindowsHighestUserAddress(common.AbstractWindowsParameterHook):
"""The highest address for user mode/kernel mode division."""
name = "highest_usermode_address"
def calculate(self):
result = self.session.profile.get_constant_object(
"MmHighestUserAddress", "Pointer").v()
# Sometimes the pointer is not present, in that case we use hardcoded
# values. I dont think these values will ever change, maybe we should
# just hard code them anyway.
if result == 0:
if self.profile.metadata("arch") == "AMD64":
result = 0x7fffffeffff
result = 0x7ffeffff
return result
class DTB2TaskMap(common.AbstractWindowsParameterHook):
"""Maps the DTB to the _EPROCESS structs."""
name = "dtb2task"
def calculate(self):
result = {}
for task in self.session.plugins.pslist().filter_processes():
result[int(task.dtb)] = task.obj_offset
return result
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