A Kentucky man has pleaded guilty to federal charges he developed, marketed, and provided technical support for software he knew customers used illegally to take control of other people’s computers.

Colton Grubbs used the handle KFC Watermelon to advertise the LuminosityLink administrative tool on Hackforums[dot]net, federal prosecutors alleged in an indictment filed last month. The indictment said the tool provided a variety of malicious capabilities including the ability for purchasers to control others’ computers, surreptitiously record users’ activities, and to view their files, login credentials, and personal information. The defendant, prosecutors said, also used the hacker forum and a website located at luminosity[dot]link to teach users how to conceal their identities and prevent antivirus programs from detecting the tool.

On Monday, Grubbs signed a plea agreement that admitted that from 2015 to 2017 he designed LuminosityLink and sold it for $40 apiece to more than 6,000 individuals, knowing that some of them were using it maliciously. While previously claiming the software was a legitimate tool for system administrators, Monday’s plea agreement admitted he knew some customers were using it to control computers without owners’ knowledge or permission. The document, which was signed by Grubbs, stated: