Solid Oak Software claims the Green Dam "censorware" that the Chinese government has ordered pre-installed on every PC sold in China starting July 1 contains programming code and proprietary encryption techniques from its anti-pornography CyberSitter package.

In fact, it thinks that Green Dam is largely its code.

The California publisher says it intends to seek an injunction preventing U.S. OEMs from shipping computers with the Green Dam software, adding to the international brouhaha that has flamed up since the Chinese edict became known last week. Lawyers say it would have to sue in China.

The University of Michigan, which confirmed the poaching - including blacklists and an encrypted 2004 CyberSitter news bulletin - also found Green Dam full of security vulnerabilities that could easily be used to turn PCs in zombies (see http://www.cse.umich.edu/~jhalderm/pub/gd/).

The school, which confirmed that the software blocks politically sensitive material as well as adult content, said, "Any web site a Green Dam user visits can take control of the PC," allowing malicious sites to steal private data, send spam or use the computer in a botnet.

It attributed the defects to "unsafe and outdated programming practices" and said the software needs "extensive changes."

China Daily says the Chinese government has told Green Dam designer Jinhui Computer System Engineering Company to fix it.

Jinhui also deleted the BSD license from the open source software it used, according to programmers on SourceForge quoted by the Register.