A Russian programmer accused by Microsoft of being behind the Kelihos botnet has protested his innocence.

Last week, Microsoft accused Andrey Sabelnikov of being responsible for the operations of the Kelihos botnet, saying that he had written the code for, and either created or participated in creating, the malware; it also claimed that he registered more than 3,700 ‘cz.cc' sub-domains, which were used to control and operate the botnet.

It was also revealed that Sabelnikov had worked as a software engineer and project manager at Russian anti-virus firm Agnitum, a provider of firewalls, anti-virus and security software. Sabelnikov said that upon arriving in the US on 21 January, he learned from the press that he was accused of a felony in connection with the activities of a botnet.

In a statement, Sabelnikov said: “I am a programmer with nine years' experience, graduated from St. Petersburg State University of Aerospace Instrumentation in 2003, [and have worked] in the highly respected Russian and international IT companies.

“I did not commit this crime, have never participated in the management of botnets or any other similar programs, and especially not extracted from it any benefit.”

He said that "feeling helpless in this situation and not having sufficient funds to qualified legal assistance", he returned to Russia "in a familiar environment to me to defend my innocence".

He added: “I want to emphasise that I do not have any relation to... Kelihos and spam. Unfortunately, an avalanche of press coverage... unwittingly caused the companies in which I worked and [me] personally a huge moral hazard and impact on business reputation.”

Microsoft reported the takedown of Kelihos in September, saying that it primarily sent out the MacDefender virus.