Refactored mvt-android adb Files module in order to keep copy of suspicious payloads

mvt/android/modules/adb/files.py

@@ -5,6 +5,7 @@
 
 import datetime
 import logging
+import os
 import stat
 
 from mvt.common.utils import convert_timestamp_to_iso
@@ -13,6 +14,15 @@ from .base import AndroidExtraction
 
 log = logging.getLogger(__name__)
 
+ANDROID_TMP_FOLDERS = [
+    "/tmp/",
+    "/data/local/tmp/",
+]
+ANDROID_MEDIA_FOLDERS = [
+    "/data/media/0",
+    "/sdcard/",
+]
+
 
 class Files(AndroidExtraction):
     """This module extracts the list of files on the device."""
@@ -25,13 +35,50 @@ class Files(AndroidExtraction):
                          log=log, results=results)
         self.full_find = False
 
+    def serialize(self, record: dict) -> None:
+        if "modified_time" in record:
+            return {
+                "timestamp": record["modified_time"],
+                "module": self.__class__.__name__,
+                "event": "file_modified",
+                "data": record["path"],
+            }
+
+    def check_indicators(self) -> None:
+        for result in self.results:
+            if result.get("is_suid"):
+                self.log.warning("Found an SUID file in a non-standard directory \"%s\".",
+                                 result["path"])
+
+            if self.indicators and self.indicators.check_file_path(result["path"]):
+                self.log.warning("Found a known suspicous file at path: \"%s\"", result["path"])
+                self.detected.append(result)
+
+    def backup_file(self, file_path: str) -> None:
+        local_file_name = file_path.replace("/", "_").replace(" ", "-")
+        local_files_folder = os.path.join(self.results_path, "files")
+        if not os.path.exists(local_files_folder):
+            os.mkdir(local_files_folder)
+
+        local_file_path = os.path.join(local_files_folder, local_file_name)
+
+        try:
+            self._adb_download(remote_path=file_path,
+                               local_path=local_file_path)
+        except Exception:
+            pass
+        else:
+            self.log.info("Downloaded file %s to local copy at %s",
+                          file_path, local_file_path)
+
     def find_files(self, folder: str) -> None:
         if self.full_find:
-            output = self._adb_command(f"find '{folder}' -printf '%T@ %m %s %u %g %p\n' 2> /dev/null")
+            output = self._adb_command(f"find '{folder}' -type f -printf '%T@ %m %s %u %g %p\n' 2> /dev/null")
 
             for file_line in output.splitlines():
                 [unix_timestamp, mode, size, owner, group, full_path] = file_line.rstrip().split(" ", 5)
                 mod_time = convert_timestamp_to_iso(datetime.datetime.utcfromtimestamp(int(float(unix_timestamp))))
+
                 self.results.append({
                     "path": full_path,
                     "modified_time": mod_time,
@@ -43,39 +90,10 @@ class Files(AndroidExtraction):
                     "group": group,
                 })
         else:
-            output = self._adb_command(f"find '{folder}' 2> /dev/null")
+            output = self._adb_command(f"find '{folder}' -type f 2> /dev/null")
             for file_line in output.splitlines():
                 self.results.append({"path": file_line.rstrip()})
 
-    def serialize(self, record: dict) -> None:
-        if "modified_time" in record:
-            return {
-                "timestamp": record["modified_time"],
-                "module": self.__class__.__name__,
-                "event": "file_modified",
-                "data": record["path"],
-            }
-
-    def check_suspicious(self) -> None:
-        """Check for files with suspicious permissions"""
-        for result in sorted(self.results, key=lambda item: item["path"]):
-            if result.get("is_suid"):
-                self.log.warning("Found an SUID file in a non-standard directory \"%s\".",
-                                 result["path"])
-                self.detected.append(result)
-
-    def check_indicators(self) -> None:
-        """Check file list for known suspicious files or suspicious properties"""
-        self.check_suspicious()
-
-        if not self.indicators:
-            return
-
-        for result in self.results:
-            if self.indicators.check_file_path(result["path"]):
-                self.log.warning("Found a known suspicous file at path: \"%s\"", result["path"])
-                self.detected.append(result)
-
     def run(self) -> None:
         self._adb_connect()
 
@@ -83,16 +101,27 @@ class Files(AndroidExtraction):
         if output or output.strip().splitlines():
             self.full_find = True
 
-        for data_path in ["/data/local/tmp/", "/sdcard/", "/tmp/"]:
-            self.find_files(data_path)
+        for tmp_folder in ANDROID_TMP_FOLDERS:
+            self.find_files(tmp_folder)
 
-        self.log.info("Found %s files in primary Android data directories", len(self.results))
+        for entry in self.results:
+            self.log.info("Found file in tmp folder at path %s",
+                          entry.get("path"))
+            if self.results_path:
+                self.backup_file(entry.get("path"))
+
+        for media_folder in ANDROID_MEDIA_FOLDERS:
+            self.find_files(media_folder)
+
+        self.log.info("Found %s files in primary Android tmp and media folders",
+                      len(self.results))
 
         if self.fast_mode:
             self.log.info("Flag --fast was enabled: skipping full file listing")
         else:
             self.log.info("Processing full file listing. This may take a while...")
             self.find_files("/")
+
             self.log.info("Found %s total files", len(self.results))
 
         self._adb_disconnect()