Igor’s Tip of the Week #133: Alignment items

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 […]

Igor’s Tip of the Week #132: Finding “hidden” cross-references

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 […]

Igor’s Tip of the Week #131: Advanced filters in choosers

 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 […]

Igor’s Tip of the Week #128: String list

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 […]

Igor’s Tip of the Week #127: Changing function bounds

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 […]

Igor’s Tip of the Week #126: Non-returning functions

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 […]

Igor’s Tip of the Week #121: Limiting search to an address range

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 […]

Igor’s Tip of the Week #115: Set callee address

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, […]