Although tens of millions of Windows PC users have seen these irritating programs that purport to warn against malware infections, there are few details about the operators who develop and distribute the software, known as scareware.

Financial details of the operation came to light recently after information posted by a computer hacker identifying himself as NeoN was discovered on a Russian electronic bulletin board by an American computer security researcher.

The researcher, Joe Stewart, who is director of malware research at SecureWorks of Atlanta, has tried to understand the nature of the fake antivirus software and the way it is sold through a second tier of “bot-herders,” people who redistribute the program through illegal “botnets” or networks of Internet-connected PCs.

The scheme was partially revealed, Mr. Stewart said, after NeoN broke into one of the computers used by Bakasoftware for accounting. Mr. Stewart believes the hacker posted the results of just one week’s operations.

Mr. Stewart also discovered that when the Bakasoftware program starts, it checks the language of the computer user based on information contained in the Windows operating system. If it finds the personal computer of a Russian language speaker, the program terminates.