x64dbg

What it is

A user-mode debugger with one interface for both 32-bit and 64-bit programs. It shows disassembly, registers, memory, threads, and a graph view, and saves comments and labels to a local database.

What it helps with

- Stepping through unpacking routines in malware samples
- Setting breakpoints and watching memory and register changes
- Patching executables and rebuilding imports after unpacking
- Automating tasks with its scripting language and plugins

Who it's for

Malware analysts and reverse engineers examining Windows binaries in an isolated analysis environment.

Worth knowing

Import reconstruction is built in through Scylla, which helps when dumping an unpacked process. A plugin directory lists community extensions.

Can it use debug symbols?
Yes, it has basic PDB symbol support and a source code view.

Can I write closed-source plugins for it?
Yes, its license explicitly allows closed-source plugins that run only inside x64dbg.