Belgian telecoms group Belgacom is investigating another possible hacking attempt at its international wholesale arm BICS, the group said late on Thursday.
Federal prosecutors said in September they were investigating suspected foreign state espionage against Belgacom, the dominant telecoms provider in Belgium and also a top carrier of voice traffic in Africa and the Middle East via its BICS unit.
Belgacom said it had stepped up the surveillance of its networks after the initial hacking came to light and again discovered irregularities at BICS.
"The initial investigation show that changes have been made to the software of a router, which could have happened during a recent digital intrusion," Belgacom said in a statement.
The group said it had passed on all information to the relevant authorities which continue their investigation into who is behind the hacking attempt.