The joint public-private team that is investigating the recent hacking incident at SK Telecom(SKT) is now looking into whether KT or LG Uplus may have fallen victim to similar attacks. 

According to IT authorities on Monday, the team initiated a direct investigation into the two mobile carriers last week, representing a shift away from its policy of conducting only voluntary malware inspections in the telecommunications and platform industries. 

The move comes amid speculation that the hacking group that attacked SKT using the Linux-based BPFDoor malware may have attempted to strike other domestic telecom companies as well.

The investigators are checking the KT and LG Uplus servers for malware infections by applying antivirus solutions for 202 variants of the malware used in the SKT incident.

However, so far they have reportedly found no anomalies at KT or LG Uplus that would suggest hacking.