Russian antivirus vendor Kaspersky Lab has confirmed the unauthorized online availability of its intellectual property in the form of source code and warned that it will launch legal action against people who downloaded and shared it.

In a statement sent to Softpedia, the company says that partial source code for its 2008 range of consumer products was stolen almost three years ago by a former employee.

The person responsible was quickly arrested and received a three-year suspended prison sentence for violations under Article 183 of the Russian Federation Criminal Code.

Kaspersky further confirms that it had knowledge of the source code being distributed on underground forums since as early as November 2010 and that the same files made their way onto more public websites recently.

The company continues to maintain that the leak does not affect the security of its users or products, because all critical protection technologies have been radically changed since then.

The little code that is still present verbatim is not related to any security features. Fragments of the Kaspersky antivirus engine, the most important asset of any AV business, were present in the leaked sources, but it has since been redesigned and updated.

The company warned that it is working with law enforcement authorities regarding recent developments in the case.

"The source code of Kaspersky Lab’s products is copyrighted and protected under trade secret laws. Therefore, actions including posting, downloading, using or distributing this code without the Company’s consent are illegal," the vendor said in its statement.

"Kaspersky Lab will take all appropriate legal measures against those who violate these intellectual property laws by possessing or seeking to possess, or sharing the illegally disclosed source code," it stressed.

One popular bittorrent website lists 95 active seeders (users who share) and 15 leechers (users who download) for the stolen Kaspersky source code at the moment of writing this article.

Our initial coverage of the leak is available here.