PE Structure and Sections

The summary you provided from a PE (Portable Executable) header dump displays various sections within the executable. Each section has a specific role, primarily regarding how the operating system loads and manages the executable’s data and code. Here’s an explanation of the commonly listed sections in your dump:

1. .CRT:

   • This is likely related to the C Runtime Library, containing initialization and termination code used by the runtime library.

2. .bss:

   • Represents the Block Started by Symbol section. It is used to store uninitialized global and static variables declared by the program. In the executable, this section doesn’t consume file space but is allocated in memory.

3. .data:

   • Holds initialized global and static variables. Unlike .bss, this section contains actual data values.

4. .debug_* sections:

   • These sections store debug information which is useful during debugging but not typically needed during execution. They include:
     • .debug_abbrev: Abbreviations used by the debugging data.
     • .debug_aranges: Address ranges for faster searches.
     • .debug_frame: Call frame information.
     • .debug_info: Core debugging information.
     • .debug_line: Line number information.
     • .debug_line_str: Line number string information.
     • .debug_locists: Local variable location lists.
     • .debug_pubnames: Public symbol names.
     • .debug_pubtypes: Public data type names.
     • .debug_ranges: Address ranges for variable scope.
     • .debug_rnglists: Range lists for variable scope.
     • .debug_str: String table for debug information.

5. .idata:

   • Import Directory Table. Contains information necessary for the loader to resolve DLL import function references.

6. .pdata:

   • Contains exception processing data, specifically the Function Table (used for handling exceptions on Windows).

7. .rdata:

   • Read-only data, which typically includes import tables and constant data.

8. .reloc:

   • Contains relocation information. This section is necessary for the dynamic linker to adjust memory addresses within the code when the module is loaded at a different base address than its preferred base.

9. .text:

   • Contains the executable code. This is where the compiled binary instructions reside.

10. .tls:

    • Thread Local Storage section. Contains data specific to individual threads allowing multiple threads to run the same code but use different data.

11. .xdata:

    • Extended data section, often related to enhanced exception handling or other extended features in Windows applications.

Each section serves a particular purpose, and the presence or absence of sections can vary based on how the executable was compiled and linked.