PARIS, July 21 (Reuters) - French cyber-security watchdog ANSSI warned on Wednesday of what it said were ongoing attacks against a large number of French organizations led by the China-linked APT31 hacking group. "ANSSI is currently handling a large intrusion campaign impacting numerous French entities. Attacks are still ongoing and are led by an intrusion set publicly referred as APT31," ANSSI said in an alert. "It appears from our investigations that the threat actor uses a network of compromised home routers as operational relay boxes in order to perform stealth reconnaissance as well as attacks," it added.