Two men have been arrested in connection with the botnet: a 19-year-old Dutch man who sold the software; and his Brazilian buyer.
Antivirus company Kaspersky Lab has been aiding the Dutch unit in taking down the botnet by helping affected PC owners remove the malware from their machines.
Victims of the Shadow botnet who were contacted by the Dutch police were directed to a Kaspersky page containing instructions on how to fix their machines, as well as a website giving details on how to file a complaint with the police.
However, Kaspersky's page on the botnet only tells users how to strip out the software that creates the botnet, and not any other malicious programs that the botnet could have downloaded to victims' machines.
Those who may be affected are, as usual, reminded to run a full virus scan to detect any additional malware.