Igor’s tip of the week #16: Cross-references

cross-reference, n. A reference or direction in one place in a book or other source of information to information at another place in the same work (from Wiktionary) To help you during analysis, IDA keeps track of cross-references (or xrefs for short) between different parts of the program. You can inspect them, navigate them […]

Igor’s tip of the week #14: Comments in IDA

The “I” in IDA stands for interactive, and one of the most common interactive actions you can perform is adding comments to the disassembly listing (or decompiler pseudocode). There are different types of comments you can add or see in IDA. Regular comments These comments are placed at the end of the disassembly line, delimited by an […]

Igor’s tip of the week #13: String literals and custom encodings

Most of IDA users probably analyze software that uses English or another Latin-based alphabet. Thus the defaults used for string literals – the OS system encoding on Windows and UTF-8 on Linux or macOS – are usually good enough. However, occasionally you may encounter a program which does use another language. Unicode strings In case the program […]

Igor’s tip of the week #12: Creating structures with known size

Sometimes you know the structure size but not the actual layout yet. For example, when the size of memory being allocated for the structure is fixed: In such cases, you can quickly make a dummy structure and then modify it as you analyze code which works with it. There are several approaches which can be used […]

Igor’s tip of the week #11: Quickly creating structures

When reverse engineering a big program, you often run into information stored in structures. The standard way of doing it involves using the Structures window and adding fields one by one, similar to the way you format data items in disassembly. But are there other options? Let’s look at some of them. Using already formatted data This […]

Igor’s tip of the week #10: Working with arrays

Arrays are used in IDA to represent a sequence of multiple items of the same type: basic types (byte, word, dword etc.) or complex ones (e.g. structures). Creating an array To create an array: Create the first item; Choose “Array…” from the context menu , or press *; Fill in at least the Array size field and click OK. Step 1 […]

Igor’s tip of the week #09: Reanalysis

While working in IDA, sometimes you may need to reanalyze some parts of your database, for example: after changing a prototype of an external function (especially calling convention, number of purged bytes, or “Does not return” flag); after fixing up incorrectly detected ARM/Thumb or MIPS32/MIPS16 regions; after changing global processor options (e.g. setting $gp value in MIPS or […]

Igor’s tip of the week #08: Batch mode under the hood

We’ve briefly covered batch mode last time but the basic functionality is not always enough so let’s discuss how to customize it. Basic usage To recap, batch mode can be invoked with this command line: ida -B -Lida.log <other switches> <filename> IDA will load the file, wait for the end of analysis, and write the full disassembly to […]