Binary similarity is a way to compare executable files using features such as code structure, instruction patterns, or shared functions. Unlike a simple hash comparison, which only finds identical files, similarity methods can identify related samples even when code has been changed, recompiled, or partly rewritten.
In malware analysis, this helps analysts connect a suspicious file to known samples, spot variants, and prioritize investigation. Similarity results are clues rather than proof: legitimate software can share code, and malware authors can alter or obscure code to reduce matches. Defenders should interpret a match alongside behavior, file metadata, reputation data, and other evidence-not treat it as a final verdict.