Skip to main content

Skype Protocol Reverse Engineered

He published executable files for download, which seem to be only be working with Skype 1.4, while he claims the "hard things" are already done for versions 1.x, 2..x and 4.x.

It appears that Bushmanov was able to change the Skype binary files and extract their autoupdate, obfuscation and anti0-debugging features. Most of the info Bushmanov needed seems to have come from the VanillaSkype presentation, which was given in 2006. He noted that he will be able to recruit people for his effort and complete his reverse-engineering goal.

Of course, Skype wasn't happy to hear about this project and already reacted. "We are taking all necessary steps to prevent/defeat nefarious attempts to subvert Skype's experience," the company said in a statement. "Skype takes its users' safety and security seriously and we work tirelessly to ensure each individual has the best possible experience."

The problem with Bushmanov's idea is that while reverse engineering is usually in the clear as far as copyright law is concerned, at least if it is done correctly. Bushmanov does not reverse-engineer by the book and does not follow the usual procedure, which requires monitoring of software input and output. In the end, he may still be on the hook for redistributing proprietary Skype code that is Skype's intellectual property.