v0.4.5

fixing c2 debug output blocking callbacks

CHANGELOG.md

@@ -1,4 +1,10 @@
 
+## [v0.4.5] - 2024-01-16
+
+### Changed
+
+- Updated the c2 profile sub-process code to not cause deadlocks and only keep the latest 100 messages from debug output
+
 ## [v0.4.4] - 2024-01-13
 
 ### Changed

mythic_container/__init__.py

@@ -3,7 +3,7 @@
 
 containerVersion = "v1.1.4"
 
-PyPi_version = "0.4.4"
+PyPi_version = "0.4.5"
 
 RabbitmqConnection = rabbitmqConnectionClass()
 

mythic_container/c2_utils.py

@@ -6,6 +6,7 @@
 import subprocess
 import asyncio
 import traceback
+from collections import deque
 
 
 def kill(proc_pid):
@@ -20,22 +21,43 @@ def kill(proc_pid):
         logger.exception(f"[-] Failed to kill process: {e}")
 
 
-async def deal_with_stdout(c2_profile: str) -> str:
-    output = ""
-    lines = 0
+async def keep_reading_stdout(c2_profile: str):
+    if "reading" in mythic_container.C2ProfileBase.runningServers[c2_profile]:
+        return
     while True:
+        mythic_container.C2ProfileBase.runningServers[c2_profile]["reading"] = 1
         try:
             line = await asyncio.wait_for(
                 mythic_container.C2ProfileBase.runningServers[c2_profile]["process"].stdout.readline(), timeout=3.0)
-            output += line.decode()
-            lines += 1
-            if lines > 100:
-                break
-        except asyncio.TimeoutError:
-            break
+            if line is not None:
+                if len(line) == 0:
+                    # the process has stopped, but our loop will keep returning blank lines
+                    if mythic_container.C2ProfileBase.runningServers[c2_profile]["process"].returncode is not None:
+                        del mythic_container.C2ProfileBase.runningServers[c2_profile]["reading"]
+                        return
+                if "output" in mythic_container.C2ProfileBase.runningServers[c2_profile]:
+                    mythic_container.C2ProfileBase.runningServers[c2_profile]["output"].append(line.decode())
+                else:
+                    mythic_container.C2ProfileBase.runningServers[c2_profile]["output"] = deque([line.decode()], 100)
+        except TimeoutError:
+            await asyncio.sleep(1)
+            continue
         except Exception as e:
             logger.exception(f"hit exception trying to get server output: {traceback.format_exc()}")
-            return output + traceback.format_exc()
+            del mythic_container.C2ProfileBase.runningServers[c2_profile]["reading"]
+            return
+
+
+async def deal_with_stdout(c2_profile: str) -> str:
+    output = ""
+    if "output" in mythic_container.C2ProfileBase.runningServers[c2_profile]:
+        try:
+            while True:
+                output += mythic_container.C2ProfileBase.runningServers[c2_profile]["output"].popleft()
+        except IndexError:
+            pass
+        except Exception as e:
+            logger.exception(f"hit exception trying to read server output: {traceback.format_exc()}")
     return output
 
 
@@ -421,6 +443,7 @@ async def startServerBinary(
         process = await asyncio.create_subprocess_shell(cmd=str(path), stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
                                                         shell=True, cwd=str(cwd), env=os.environ.copy())
         mythic_container.C2ProfileBase.runningServers[c2.name]["process"] = process
+        asyncio.create_task(keep_reading_stdout(c2.name))
         await asyncio.sleep(3)
         if process.returncode is not None:
             # this means something went wrong and the process is dead
@@ -521,7 +544,8 @@ async def stopServer(msg: bytes) -> bytes:
                             Message=f"Stopped server:\nOutput:{await deal_with_stdout(c2.name)}",
                             InternalServerRunning=False
                         )
-                        mythic_container.C2ProfileBase.runningServers[c2.name]["output"] = ""
+                        if "output" in mythic_container.C2ProfileBase.runningServers[c2.name]:
+                            mythic_container.C2ProfileBase.runningServers[c2.name]["output"].clear()
                         return ujson.dumps(response.to_json()).encode()
                 else:
                     # just means we've never started it before, so start it now
@@ -671,4 +695,4 @@ async def hostFile(msg: bytes) -> bytes:
             Success=False,
             Error=f"Hit exception trying to call host_file function: {traceback.format_exc()}\n{e}"
         )
-        return ujson.dumps(response.to_json()).encode()
+        return ujson.dumps(response.to_json()).encode()

setup.py

@@ -10,7 +10,7 @@
 # This call to setup() does all the work
 setup(
     name="mythic_container",
-    version="0.4.4",
+    version="0.4.5",
     description="Functionality for Mythic Services",
     long_description=README,
     long_description_content_type="text/markdown",