Agent: Only use "None" creds in powershell exploiter if host is Windows

monkey/infection_monkey/exploit/powershell.py

@@ -15,6 +15,7 @@ from infection_monkey.exploit.HostExploiter import HostExploiter
 from infection_monkey.exploit.tools.helpers import get_monkey_depth, get_target_monkey_by_os
 from infection_monkey.model import DROPPER_ARG, GET_ARCH_WINDOWS, RUN_MONKEY, VictimHost
 from infection_monkey.utils.commands import build_monkey_commandline
+from infection_monkey.utils.environment import is_windows_os
 
 LOG = logging.getLogger(__name__)
 
@@ -59,6 +60,10 @@ class PowerShellExploiter(HostExploiter):
         return None
 
     def _get_credentials(self) -> List[Tuple[Optional[str], Optional[str]]]:
+        # When username or password is None, this instructs the powershell client to attempt to use
+        # The current user's credentials. This is only valid if the client is running from a Windows
+        # machine.
+
         credentials = []
         credentials.extend(self._get_empty_credentials())
         credentials.extend(self._get_username_only_credentials())
@@ -67,10 +72,18 @@ class PowerShellExploiter(HostExploiter):
         return credentials
 
     def _get_empty_credentials(self) -> List[Tuple[None, None]]:
-        return [(None, None)]
+        if is_windows_os():
+            return [(None, None)]
 
-    def _get_username_only_credentials(self) -> List[Tuple[str, None]]:
-        return [(username, None) for username in self._config.exploit_user_list]
+        return []
+
+    def _get_username_only_credentials(self) -> List[Tuple[str, Optional[str]]]:
+        credentials = [(username, "") for username in self._config.exploit_user_list]
+
+        if is_windows_os():
+            credentials.extend([(username, None) for username in self._config.exploit_user_list])
+
+        return credentials
 
     def _get_username_password_credentials(self) -> List[Tuple[str, str]]:
         return [credentials for credentials in self._config.get_exploit_user_password_pairs()]