Skip to content

Fix missing handling of CustomBrowser MessageType#182

Open
j1ndoSH wants to merge 2 commits into
MythicAgents:masterfrom
j1ndoSH:master
Open

Fix missing handling of CustomBrowser MessageType#182
j1ndoSH wants to merge 2 commits into
MythicAgents:masterfrom
j1ndoSH:master

Conversation

@j1ndoSH

@j1ndoSH j1ndoSH commented Jun 1, 2026

Copy link
Copy Markdown

When running any ldap_query or req_query command the Agent fails to produce a response and throws the following exception.

Unhandled exception: System.Exception: Unhandled message type while generating response: CustomBrowser
   at ApolloInterop.Classes.Tasking.CreateTaskResponse(Object userOutput, Boolean completed, String status, IEnumerable`1 messages)
   at Tasks.ldap_query.Start()
   at ApolloInterop.Classes.Impersonation.ImpersonationScope.Run(WindowsIdentity identity, Action action)
   at System.Threading.Tasks.Task.Execute()

This error was fixed by adding the missing switch-case to the switch-statement in Tasking.cs, resulting in the Agent successfully reporting back LDAP and Registry information. While looking through the code I also spotted a small typo.

case MessageType.CustomBrowser:
    resp.Browser = (CustomBrowser)msg;
    break;

However this revealed a JSONSerialize error when using ldap_query without specifying which attributes to retrieve. So far it seems this error is triggered by querying multi-value attributes like member where as "simple" attributes like cn,samaccountname,description are fine. This error also crashes the Agent process.

Entry: CN=Administrators
  Metadata[DistinguishedName]: String = LDAP://CN=Administrators,CN=Builtin,DC=ludus,DC=domain
  Metadata[member]: String[][3]
  Metadata[cn]: String = Administrators
JsonSerializer Execption Stacktrace
System.Management.Automation.RemoteException
Unhandled Exception: System.Runtime.Serialization.SerializationException: Type 'System.Collections.Generic.List`1[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]' with data contract name 'ArrayOfstring:http://schemas.microsoft.com/2003/10/Serialization/Arrays' is not expected. Consider using a DataContractResolver if you are using DataContractSerializer or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to the serializer.
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.VerifyType(DataContract dataContract, Type declaredType)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.HandleCollectionAssignedToObject(Type declaredType, DataContract& dataContract, Object& obj, Boolean& verifyKnownType)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.SerializeWithXsiType(XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle objectTypeHandle, Type objectType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle, Type declaredType)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContextComplex.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerializeReference(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at WriteKeyValueOfstringanyTypeToJson(XmlWriterDelegator , Object , XmlObjectSerializerWriteContextComplexJson , ClassDataContract , XmlDictionaryString[] )
   at System.Runtime.Serialization.Json.JsonClassDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
   at WriteArrayOfKeyValueOfstringanyTypeToJson(XmlWriterDelegator , Object , XmlObjectSerializerWriteContextComplexJson , CollectionDataContract )
   at System.Runtime.Serialization.Json.JsonCollectionDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContextComplex.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerializeReference(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at WriteCustomBrowserEntryToJson(XmlWriterDelegator , Object , XmlObjectSerializerWriteContextComplexJson , ClassDataContract , XmlDictionaryString[] )
   at System.Runtime.Serialization.Json.JsonClassDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContextComplex.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at WriteArrayOfCustomBrowserEntryToJson(XmlWriterDelegator , Object , XmlObjectSerializerWriteContextComplexJson , CollectionDataContract )
   at System.Runtime.Serialization.Json.JsonCollectionDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContextComplex.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerializeReference(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at WriteCustomBrowserToJson(XmlWriterDelegator , Object , XmlObjectSerializerWriteContextComplexJson , ClassDataContract , XmlDictionaryString[] )
   at System.Runtime.Serialization.Json.JsonClassDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContextComplex.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at WriteMythicTaskResponseToJson(XmlWriterDelegator , Object , XmlObjectSerializerWriteContextComplexJson , ClassDataContract , XmlDictionaryString[] )
   at System.Runtime.Serialization.Json.JsonClassDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContextComplex.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at WriteArrayOfMythicTaskResponseToJson(XmlWriterDelegator , Object , XmlObjectSerializerWriteContextComplexJson , CollectionDataContract )
   at System.Runtime.Serialization.Json.JsonCollectionDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContextComplex.InternalSerialize(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.InternalSerializeReference(XmlWriterDelegator xmlWriter, Object obj, Boolean isDeclaredType, Boolean writeXsiType, Int32 declaredTypeID, RuntimeTypeHandle declaredTypeHandle)
   at WriteTaskingMessageToJson(XmlWriterDelegator , Object , XmlObjectSerializerWriteContextComplexJson , ClassDataContract , XmlDictionaryString[] )
   at System.Runtime.Serialization.Json.JsonClassDataContract.WriteJsonValueCore(XmlWriterDelegator jsonWriter, Object obj, XmlObjectSerializerWriteContextComplexJson context, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.Json.XmlObjectSerializerWriteContextComplexJson.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph)
   at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.WriteObject(XmlDictionaryWriter writer, Object graph)
   at System.Runtime.Serialization.Json.DataContractJsonSerializer.WriteObject(Stream stream, Object graph)
   at ApolloInterop.Serializers.JsonSerializer.Serialize(Object msg)
   at ApolloInterop.Serializers.EncryptedJsonSerializer.Serialize(Object msg)
   at HttpTransport.HttpProfile.SendRecv[T,TResult](T message, OnResponse`1 onResponse)
   at HttpTransport.HttpProfile.<>c__DisplayClass19_0.<GetTasking>b__0(TaskingMessage msg)
   at Apollo.Management.Tasks.TaskManager.CreateTaskingMessage(OnResponse`1 onResponse)
   at HttpTransport.HttpProfile.Start()
   at Apollo.Agent.Apollo.Start()
   at Apollo.Program.Main(String[] args)

While this fix made reg_query and ldap_query usable again I don't know how to properly address the JSONSerialize error. Converting these String[][3] into a value separated string before serializing fixes the issue but looks a bit "ugly" in the CustomBrowser.


Versions of Agents/C2Proiles involved

  • apollo:v0.0.1.15
  • registry_browser:v0.0.1.1
  • ldap_browser:v0.0.1
  • http:v0.0.3.2

Versions of Mythic:

  • mythic-cli version: v0.3.26
  • Mythic Server version: v3.4.35
  • React UI Version: v0.3.112

@its-a-feature

Copy link
Copy Markdown
Contributor

Thanks for finding this! I'll look into this PR and see if I can address that serialization issue

@j1ndoSH

j1ndoSH commented Jun 9, 2026

Copy link
Copy Markdown
Author

Great to hear, looking to forward to your input.

My current solution (which is not yet part of the PR) is a small change in the ExtractEntry function in ldap_query.cs on line 168.

//original code
entry[propertyName] = values;

// changed code
entry[propertyName] = string.Join(" | ", values);

That way multi-valued attributes are serialized as a simple string, just like the single valued attributes.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

3 participants