micro hook

Author: David Zimmer
Date: 09.11.12 - 9:41pm

Had one more idea for a new hook type to experiment with that would give a "2 byte" hook.

The trick lays in scanning back from the APIs start address to figure out how many alignment bytes are present. (0x90 and 0xCC)

For the 25 apis i tested in sclog, this was usually 5 bytes, which is enough for a relative E9 jump. Which means you only have to overwrite 2 bytes of the actual API opcodes.

  E9 xxxxxxxx   jmp 0x11111111 <--in func preamble (5 bytes)
  EB F9         jmp short here <--api entry point  (2 bytes)

I will run this test on x64 and see how many pre align bytes they usually have, maybe it will help there. If not I will just remove it and revert to the previous commit. Supporting this idea made the hooking code more complex than its probably worth unless the preamble trick really makes a difference on the x64 side.

Comments: (0)

Leave Comment:
Email: (not shown)
Message: (Required)
Math Question: 13 + 55 = ? followed by the letter: P 

About Me
More Blogs
Main Site
Yara WorkBench
vbdec dbg updates
vb6 PCode NOP
vb6 API and call backs
how pcode works Pt1
Reversing PCode Args
VB6 PCode Disassembly
VB6 PCode Debugger
UConnect Disable Cell Modem
IDA python over IPC
dns wildcard blocking
64bit IDA Plugins
anterior lines
misc news/updates
Decoders again
CDO.Message Breakpoints
SysAnalyzer Updates
SysAnalyzer and Site Updates
crazy decoder
ida js w/dbg
flash patching #2
JS Graphing
packet reassembly
Delphi IDA Plugin
scdbg IDA integration
API Hash Database
Winmerge plugin
IDACompare Updates
Guest Post @ hexblog
TCP Stream Reassembly
SysAnalyzer Updates
Apilogger Video
Shellcode2Exe trainer
scdbg updates
IDA Javascript w/IDE
Rop Analysis II
scdbg vrs ROP
flash patching
x64 Hooks
micro hook
jmp api+5 *2
SysAnalyzer Updates
InjDll runtime config
C# Asm/Dsm Library
Shellcode Hook Detection
Updates II
Java Hacking
Windows 8
Win7 x64
Graphing ideas
.Net Hacking
Old iDefense Releases
hll shellcode
ActionScript Tips
-patch fu
scdbg ordinal lookup
scdbg -api mode
Peb Module Lists
scdbg vrs Process Injection
GetProcAddress Scanner
scdbg fopen mode
scdbg findsc mode
scdbg MemMonitor
demo shellcodes
scdbg download
api hashs redux
Api hash gen
Retro XSS Chat Codes
Exe as DLL
Olly Plugins
Debugging Explorer
Attach to hidden process
JS Refactoring
Asm and Shellcode in CSharp
Fancy Return Address
PDF Stream Dumper
Malcode Call API by Hash
WinDbg Cheat Sheet
GPG Automation