Police said the two made about $877,000 from the coughing program. They marketed the system as well as cellular subscriber information to telephone selling organizations which used information to contact clients to obtain them to switch to other cellular providers.
Authorities said a former KT worker and six others were also charged for their tasks in the program.
The information robbery at KT took place over the span of five several weeks from Feb and impacted about half of KT's 16 million cellular clients.
KT apologized and said it will beef up its security system.
The occurrence is the latest in a series of large-scale coughing attacks that have impacted millions in one of the most wired countries. Last year, online hackers took individual information of 13 million gamers at Nexon and private information of 35 million members at web website Nate and Cyworld were published.