State-of-the-art binary code analysis tools
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 […]
When analyzing regular, well-formed binaries, you can usually rely on IDA’s autoanalysis to create functions and detect their boundaries correctly. However, there may be situations when IDA’s guesses need to be adjusted. Non-returning calls One example could be calls to non-returning functions. Let’s say a function has been misdetected by IDA as non-returning: But on further analysis […]
Some functions in programs do not return to caller: well-known examples include C runtime functions like exit(), abort(), assert() but also many others. Modern compilers can exploit this knowledge to optimize the code better: for example, the code which would normally follow such a function call does not need to be generated which decreases the […]
When performing a search in IDA, it by default starts from the current position and continues up to the maximum address in the database (or to the minimal for searches “Up”). This works well enough for small to average files, but can get pretty slow for big ones, or especially in case of debugging […]
Cross-references is one of the most useful features of IDA. For example, they allow you to see where a particular function is being called or referenced from, helping you to see how the function is used and understand its behavior better or discover potential bugs or vulnerabilities. For direct calls, IDA adds cross-references automatically, […]
Many keyboard shortcuts have been described on this blog, but they may be difficult to retain, especially if you don’t use them every day. To remedy that, we have been publishing a cheat sheet with the most common ones. You can find it linked from our documentation page in HTML or PDF […]