Accellion, the third-party vendor hired by Singapore Telecommunications (Singtel), says its file-sharing system FTA has been illegally attacked by hackers who have yet to be identified.

The system is a standalone system that’s used to share information both internally and externally.

Customer information may have been compromised, according to Singtel in a filing on Feb 11.

SEE: Singtel and Ericsson to deploy high-end 5G connectivity in Singapore

According to Accellion, the incident is part of a wider concerted attack against users of their file sharing system.

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Singtel says it has suspended all use of the system and activated investigations. It is also currently working with cyber security experts and the relevant authorities, including the Cyber Security Agency of Singapore.

“This is an isolated incident involving a standalone third-party system. Our core operations remain unaffected and sound,” it says.

Shares in Singtel closed flat at $2.40 on Feb 11.