Add the suspended threads plugin from DEF CON 2024

2026-09-29 04:54:51 +02:00 · 2024-12-21 12:18:23 -06:00
parent 6262fcf315
commit a84d361113
1 changed files with 147 additions and 0 deletions
@@ -0,0 +1,147 @@
+import logging
+
+from typing import Dict
+from functools import partial
+
+from volatility3.framework import renderers, interfaces, exceptions
+from volatility3.framework.configuration import requirements
+from volatility3.framework.renderers import format_hints
+import volatility3.plugins.windows.pslist as pslist
+import volatility3.plugins.windows.threads as threads
+import volatility3.plugins.windows.pe_symbols as pe_symbols
+
+from volatility3.framework.objects import utility
+
+vollog = logging.getLogger(__name__)
+
+
+class SuspendedThreads(interfaces.plugins.PluginInterface):
+    """Enumerates suspended threads."""
+
+    _required_framework_version = (2, 13, 0)
+    _version = (1, 0, 0)
+
+    @classmethod
+    def get_requirements(cls):
+        return [
+            requirements.ModuleRequirement(
+                name="kernel",
+                description="Windows kernel",
+                architectures=["Intel32", "Intel64"],
+            ),
+            requirements.VersionRequirement(
+                name="pslist", component=pslist.PsList, version=(2, 0, 0)
+            ),
+            requirements.VersionRequirement(
+                name="pe_symbols", component=pe_symbols.PESymbols, version=(1, 0, 0)
+            ),
+            requirements.VersionRequirement(
+                name="threads", component=threads.Threads, version=(1, 0, 0)
+            ),
+        ]
+
+    def _generator(self):
+        """
+        The goal of this plugin is to report on threads that are suspended
+
+        Legitimate programs can start threads suspended but then will later resume them
+
+        Subsets of malware techniques, such as EDR evasion and process hollowing,
+        create suspended threads and do not resume them. These are the threads that this
+        plugin is designed to catch.
+
+        See the whitepaper from our DEF CON 2024 presentation for more details:
+
+        https://www.volexity.com/wp-content/uploads/2024/08/Defcon24_EDR_Evasion_Detection_White-Paper_Andrew-Case.pdf
+        """
+        kernel = self.context.modules[self.config["kernel"]]
+
+        vads_cache: Dict[int, pe_symbols.PESymbols.ranges_type] = {}
+
+        proc_modules = None
+
+        # walk the threads of each process checking for suspended threads
+        for proc in pslist.PsList.list_processes(
+            context=self.context,
+            layer_name=kernel.layer_name,
+            symbol_table=kernel.symbol_table_name,
+        ):
+            for thread in threads.Threads.list_threads(kernel, proc):
+                try:
+                    # we only care if the thread is suspended
+                    if thread.Tcb.SuspendCount == 0:
+                        continue
+
+                    # 4 == terminated
+                    if thread.Tcb.State == 4:
+                        continue
+
+                    owner_proc = thread.owning_process()
+                    owner_proc_pid = thread.Cid.UniqueProcess
+                    owner_proc_name = utility.array_to_string(owner_proc.ImageFileName)
+                    thread_tid = thread.Cid.UniqueThread
+                    thread_start_addr = thread.StartAddress
+                    thread_win32_addr = thread.Win32StartAddress
+                except exceptions.InvalidAddressException:
+                    continue
+
+                # Nothing useful to report if a process doesn't have VADs.. Also a sign of smear/terminated
+                vads = pe_symbols.PESymbols.get_vads_for_process_cache(vads_cache, owner_proc)
+                if not vads:
+                    continue
+
+                # Only compute this if needed as its expensive and 99.9% of samples
+                # will not have suspended threads
+                if not proc_modules:
+                    proc_modules = pe_symbols.PESymbols.get_process_modules(
+                        self.context, kernel.layer_name, kernel.symbol_table_name, None
+                    )
+
+                    path_and_symbol = partial(
+                        pe_symbols.PESymbols.path_and_symbol_for_address,
+                        self.context,
+                        self.config_path,
+                        proc_modules,
+                    )
+
+                start_file, start_sym = path_and_symbol(vads, thread_start_addr)
+                win32_file, win32_sym = path_and_symbol(vads, thread_win32_addr)
+
+                # the only false positive found in mass scanning of samples
+                if start_file and start_file.endswith("\\WorkFoldersShell.dll"):
+                    continue
+
+                if win32_file and win32_file.endswith("\\WorkFoldersShell.dll"):
+                    continue
+
+                yield (
+                    0,
+                    (
+                        owner_proc_name,
+                        owner_proc_pid,
+                        thread_tid,
+                        start_file or renderers.NotAvailableValue(),
+                        start_sym or renderers.NotAvailableValue(),
+                        format_hints.Hex(thread_start_addr),
+                        win32_file or renderers.NotAvailableValue(),
+                        win32_sym or renderers.NotAvailableValue(),
+                        format_hints.Hex(thread_win32_addr),
+                    ),
+                )
+
+    def run(self):
+        return renderers.TreeGrid(
+            [
+                ("Process", str),
+                ("PID", int),
+                ("TID", int),
+                ("StartFile", str),
+                ("StartSymbol", str),
+                ("StartAddress", format_hints.Hex),
+                ("Win32StartFile", str),
+                ("Win32StartSymbol", str),
+                ("Win32StartAddress", format_hints.Hex),
+            ],
+            self._generator(),
+        )
+