the National Cyber Security Centre to report the incident online (or the NCSC incident helpline – 0300 200 973 if there is no access to ICT);
y Ganolfan Seiberddiogelwch Genedlaethol i gyflwyno adroddiad ar-lein am y digwyddiad (neu linell gymorth digwyddiadau’r NCSC – 0300 200 973 os nad oes mynediad at TGCh);