The group behind the attacks have previously claimed attacks on Iranian targets, experts said.

The long-running operation involved hijacked email accounts, phony login pages and a legitimate ID verification service.

The new group is suspected of collaborating with "multiple" Iranian-linked hacking efforts.

Sites were restored Monday afternoon, the Israeli government said.

The attack is just the latest in a string of apparent influence operations targeting civilians in Israel and Iran.

The group is one of a number of hacking outlets carrying out ransomware incidents from the Middle East, according to Microsoft specialists.