epthook.cpp File Reference

!epthook command More...

#include "pch.h"

Functions
VOID	CommandEptHookHelp ()
	help of the !epthook command
VOID	CommandEptHook (vector< string > SplitCommand, string Command)
	!epthook command handler

Detailed Description

!epthook command

Author

Sina Karvandi (sina@.nosp@m.hype.nosp@m.rdbg..nosp@m.org)

Version

0.1

Date

2020-07-10

Copyright

This project is released under the GNU Public License v3.

Function Documentation

CommandEptHook()

VOID CommandEptHook	(	vector< string >	SplitCommand,
		string	Command )

!epthook command handler

Parameters

SplitCommand
Command

Returns

VOID

{
    PDEBUGGER_GENERAL_EVENT_DETAIL     Event                 = NULL;
    PDEBUGGER_GENERAL_ACTION           ActionBreakToDebugger = NULL;
    PDEBUGGER_GENERAL_ACTION           ActionCustomCode      = NULL;
    PDEBUGGER_GENERAL_ACTION           ActionScript          = NULL;
    UINT32                             EventLength;
    UINT32                             ActionBreakToDebuggerLength = 0;
    UINT32                             ActionCustomCodeLength      = 0;
    UINT32                             ActionScriptLength          = 0;
    BOOLEAN                            GetAddress                  = FALSE;
    UINT64                             OptionalParam1              = 0; // Set the target address
    vector<string>                     SplitCommandCaseSensitive {Split(Command, ' ')};
    UINT32                             IndexInCommandCaseSensitive = 0;
    DEBUGGER_EVENT_PARSING_ERROR_CAUSE EventParsingErrorCause;
 
    if (SplitCommand.size() < 2)
    {
        ShowMessages("incorrect use of the '!epthook'\n");
        CommandEptHookHelp();
        return;
    }
 
    //
    // Interpret and fill the general event and action fields
    //
    if (!InterpretGeneralEventAndActionsFields(
            &SplitCommand,
            &SplitCommandCaseSensitive,
            HIDDEN_HOOK_EXEC_CC,
            &Event,
            &EventLength,
            &ActionBreakToDebugger,
            &ActionBreakToDebuggerLength,
            &ActionCustomCode,
            &ActionCustomCodeLength,
            &ActionScript,
            &ActionScriptLength,
            &EventParsingErrorCause))
    {
        return;
    }
 
    //
    // Check here to make sure that the user didn't specified the calling stages for this ept hook
    //
    if (Event->EventStage != VMM_CALLBACK_CALLING_STAGE_PRE_EVENT_EMULATION)
    {
        ShowMessages("the utilization of 'post' or 'all' event calling stages is not meaningful "
                     "for the hidden hook; therefore, this command does not support them\n");
 
        FreeEventsAndActionsMemory(Event, ActionBreakToDebugger, ActionCustomCode, ActionScript);
        return;
    }
 
    //
    // Interpret command specific details (if any)
    //
    for (auto Section : SplitCommand)
    {
        IndexInCommandCaseSensitive++;
 
        if (!Section.compare("!epthook"))
        {
            continue;
        }
        else if (!GetAddress)
        {
            //
            // It's probably address
            //
            if (!SymbolConvertNameOrExprToAddress(
                    SplitCommandCaseSensitive.at(IndexInCommandCaseSensitive - 1),
                    &OptionalParam1))
            {
                //
                // Couldn't resolve or unknown parameter
                //
                ShowMessages("err, couldn't resolve error at '%s'\n\n",
                             SplitCommandCaseSensitive.at(IndexInCommandCaseSensitive - 1).c_str());
                CommandEptHookHelp();
 
                FreeEventsAndActionsMemory(Event, ActionBreakToDebugger, ActionCustomCode, ActionScript);
                return;
            }
            else
            {
                GetAddress = TRUE;
            }
        }
        else
        {
            //
            // Unknown parameter
            //
            ShowMessages("unknown parameter '%s'\n\n", Section.c_str());
            CommandEptHookHelp();
 
            FreeEventsAndActionsMemory(Event, ActionBreakToDebugger, ActionCustomCode, ActionScript);
            return;
        }
    }
    if (OptionalParam1 == 0)
    {
        ShowMessages("please choose an address to put the hidden breakpoint on it\n");
 
        FreeEventsAndActionsMemory(Event, ActionBreakToDebugger, ActionCustomCode, ActionScript);
        return;
    }
 
    //
    // Set the optional parameters
    //
    Event->Options.OptionalParam1 = OptionalParam1;
 
    //
    // Send the ioctl to the kernel for event registration
    //
    if (!SendEventToKernel(Event, EventLength))
    {
        //
        // There was an error, probably the handle was not initialized
        // we have to free the Action before exit, it is because, we
        // already freed the Event and string buffers
        //
 
        FreeEventsAndActionsMemory(Event, ActionBreakToDebugger, ActionCustomCode, ActionScript);
        return;
    }
 
    //
    // Add the event to the kernel
    //
    if (!RegisterActionToEvent(Event,
                               ActionBreakToDebugger,
                               ActionBreakToDebuggerLength,
                               ActionCustomCode,
                               ActionCustomCodeLength,
                               ActionScript,
                               ActionScriptLength))
    {
        //
        // There was an error
        //
 
        FreeEventsAndActionsMemory(Event, ActionBreakToDebugger, ActionCustomCode, ActionScript);
        return;
    }
}

CommandEptHookHelp()

VOID CommandEptHookHelp

(

)

help of the !epthook command

Returns

VOID

{
    ShowMessages("!epthook : puts a hidden-hook EPT (hidden breakpoints).\n\n");
 
    ShowMessages(
        "syntax : \t!epthook [Address (hex)] [pid ProcessId (hex)] [core CoreId (hex)] "
        "[imm IsImmediate (yesno)] [buffer PreAllocatedBuffer (hex)] [script { Script (string) }] "
        "[asm condition { Condition (assembly/hex) }] [asm code { Code (assembly/hex) }] [output {OutputName (string)}]\n");
 
    ShowMessages("\n");
    ShowMessages("\t\te.g : !epthook nt!ExAllocatePoolWithTag\n");
    ShowMessages("\t\te.g : !epthook nt!ExAllocatePoolWithTag+5\n");
    ShowMessages("\t\te.g : !epthook fffff801deadb000\n");
    ShowMessages("\t\te.g : !epthook fffff801deadb000 pid 400\n");
    ShowMessages("\t\te.g : !epthook fffff801deadb000 core 2 pid 400\n");
    ShowMessages("\t\te.g : !epthook fffff801deadb000 script { printf(\"hook triggered at: %%llx\\n\", $context); }\n");
    ShowMessages("\t\te.g : !epthook fffff801deadb000 asm code { nop; nop; nop }\n");
}