State-of-the-art binary code analysis tools
When decompiling code without high-level metadata (especially firmware), you may observe strange-looking address expressions which do not seem to make sense. What are these and how to fix/improve the pseudocode? Because on the CPU level there is no difference between an address and a simple number, distinguishing addresses and plain numbers is a difficult task which […]
When working on a binary, you often recover types used in it from many sources: creating structures manually, from data, or using decompiler; parsing header files; importing them from type libraries or debug information; However, it may happen that eventually you discover duplicates. For example, you find out that the “custom” structure you’ve been […]
Previosuly, we’ve covered creating structures from C code using the Local Types window, however this may be not very convenient when you have complex types with many dependencies (especially of scattered over several fiels or depending on preprocessor defines). In such case it may be nore convenient to parse the original header file(s) on […]
Some of the processors supported by IDA support different ISA variants, in particular: ARM processor module supports the classic 32-bit ARM instructions (A32), 16-bit Thumb or mixed 16/32-bit Thumb32 (T32) , as well as 64-bit A64 instructions (A64) PPC processor module supports the standard 32-bit PowerPC instructions and mixed 16/32-bit Variable Length Environment (VLE) MIPS module supports the […]
Although most of the time you can probably do all of the reversing inside IDA, occasionally you may need to continue it using other tools. While sometimes it may be enough to analyze the input file with another tool, or use the Export Data feature, the disassembly listing is more convenient in many cases. […]
Sometimes you may see mysterious align keywords in the disassembly, which can appear both in code and data areas: Usually they’re only apparent in the text view. These directives are used by many assemblers to indicate alignment to a specific address boundary, usually a power of two. IDA uses it to replace potentially irrelevant bytes by a […]
When analyzing firmware or other binaries without metadata, IDA is not always able to discover and analyze all functions which means the cross-references can be missing. Let’s say you found a string in the binary (e.g. in the String list) which has no cross references, but you’re reasonably sure it’s actually used. How to […]
We’ve covered choosers previously and talked about searching, sorting and filtering. The default filter (Ctrl–F shortcut) is pretty simple: it performs case-insensitive match on any column of the list. Advanced filters Advanced filter dialog is accessible via the context menu entry “Modify filters…” or the shortcut Ctrl–Shift–F In the dialog you can: match any or a specific […]
Using the string list is one way to look for text in the binary but it has its downsides: building the list takes time for big binaries, some strings may be missing initially so you may need several tries to get the options right, and then you need to actually find what you need […]
When exploring an unfamiliar binary, it may be difficult to find interesting places to start from. One common approach is to check what strings are present in the program – this might give some hints about its functionality and maybe some starting places for analysis. While you can scroll through the listing and look at […]