Open sourcing makes computer source code public and possibly available for custom modifications. Skype software makes voice and video calls possible on the Internet.
The hacker, Efim Bushmanov, describes himself as a "freelance researcher" and is based in the Komi Republic, a subject republic of Russia about 870 miles from Moscow, the San Francisco Chronicle reported.
Bushmanov said in addition to making Skype open source, he wants to find "friends who can spend many hours" to complete the task, the report said.
Skype's operators, headquartered in Luxembourg, say they are ensuring their customers' safety and security, and the Chronicle said there are indications legal action will be taken against Bushmanov and anyone else who uses the code.
Meanwhile, Bushmanov is not hiding, practically issuing a "come and get me" challenge to Skype, the Chronicle said.
Why is he doing it? "I become famous," he said on his Google blog, posting links to interviews, the Chronicle said.