The white-bearded rabbi had an unusual message for his followers in Israel. Instead of presenting a teaching from the Torah, he exhorted them in a widely distributed video clip to avoid the temptation of spying for Iran.

“Heaven forbid, there are those who cooperate with them,” declared Yigal Cohen, a member of Israel’s chief rabbinical council with a large and influential social media presence.

It was unexpected messaging but hardly random. Rabbi Cohen said that Israeli security officials had approached him and asked him to warn listeners that Iranian agents were recruiting people in Israel to work for them — urging them over the internet to photograph locations, acquire guns and hide them in a set location, and potentially even kill.

“I am begging you, there is no greater blasphemy than seeing a Torah-abiding, observant Jew betray his people,” the rabbi said in the video, adding that any such contact with Iranian agents would end in jail time and ruin lives.

Israeli authorities have long been warning through public awareness campaigns that Iranian intelligence agents are recruiting informers and operatives inside Israel. Enlisting Rabbi Cohen and other rabbis was part of a broad array of countermeasures Israel is taking against an adversary that police and prosecutors say is seeking new ways to gain advantage.

Israeli prosecutors have served indictments in recent months against soldiers and civilians, religious and secular Israelis, Jews and Arabs. In all, prosecutors have obtained indictments in more than 60 cases, the police said.

“A number of suspects have been exposed for spying for the enemy,” Amichai Panetta, a police investigator, said in a statement late last month, adding, “Some of them carried out their deeds during wartime and helped the enemy realize its plans on Israeli soil.”

One of the latest suspects, arrested on June 9, is a U.S. citizen who was studying in an ultra-Orthodox seminary in Jerusalem. He is accused of maintaining contact with an Iranian intelligence agent and harming state security, after photographing sensitive sites for payment, according to the indictment.

The U.S. Embassy in Jerusalem declined to comment, citing “privacy and other considerations.” Iranian government officials did not respond to emailed requests for comment.

Iran has focused on recruiting low-level amateur sleuths since the October 2023 Hamas-led attack on Israel and increased those efforts after Israel’s first offensive against Iran in June 2025, the Israeli police said. Israeli authorities have struggled to contain the problem.

Iran’s agents cast a wide net, mostly over the Telegram messaging app, Israeli authorities said, using phony names and initially offering new recruits easy money for simple tasks, like taking photographs or video footage of their neighborhood. The Iranians then escalate the requests over time to assignments like gathering information about critical infrastructure and systems, including Israel’s air defenses, the police and a former security official said.

Those who have been caught are held in detention and prosecuted. A military court sentenced a soldier to a five-year prison term this month after he sent video footage to an Iranian agent showing missile interceptions during the June 2025 conflict, according to a statement from the military.

Some of the cases are subject to gag orders and heard behind closed doors. As in many such security cases, few details were available about the status of the proceedings against the American citizen.

A review of the cases being prosecuted shows that the recruits hail from all walks of Israeli life. Mostly male, they include immigrants from the former Soviet Union, active and former Israeli soldiers, and, in at least nine cases, members of the ultra-Orthodox community, known in Hebrew as Haredim.

Most ultra-Orthodox Israeli men refuse to perform military service, but many have modernized and use smartphones on which they can access the internet.

Israel Cohen, a prominent Haredi commentator and social media influencer, also helped authorities with their campaign to stop Iranian recruitment. He broadcast warnings on his radio show and connected security figures with several rabbis, as well as Haredi public figures and opinion makers.

Mr. Cohen said the Haredi public was “in shock” at first over reports that members of its ranks had worked for Iran. But the community soon “understood the need to warn against the danger and stop it” before it spread further, he said.

The effort is ongoing. In early July, another Haredi journalist and social media influencer posted an additional appeal to the ultra-Orthodox public in Yiddish.

The low-level Iranian operations bear little resemblance to the sophisticated espionage methods Israeli intelligence uses. Instead, they appear to rely more on wide-scale fishing expeditions and luck, according to Israeli security officials and experts.

One night in May, for example, in outreach that was hardly clandestine, thousands of Israelis received text messages inviting them “to cooperate in the field of intelligence” by contacting an Iranian embassy abroad or an Iranian cyber operative online.

“My wife gets an S.M.S. every other day claiming to be from Iranian intelligence and offering a big reward,” said Shalom Ben Hanan, a former Shin Bet official who is regularly briefed on the matter by the agency. Out of thousands of attempts, if Iran manages to recruit one or two, “that’s a success,” he said.

It is unclear how much harm Iran’s online recruitment efforts have inflicted on Israel, while Israel’s intelligence operations have done great damage to Iran, including contributing to the decapitation of its former leadership. But the Israeli authorities certainly take Iran’s efforts seriously.

In April, the police and Shin Bet arrested a 22-year-old man from Haifa and charged him with manufacturing explosives as part of a plot to kill a senior Israeli political figure. The accused man experimented with explosions in a parking lot and, at the behest of his Iranian handlers, photographed Haifa’s port and Iranian missile impact sites during the most recent war, the authorities said.

Another case that raised alarms involved a reserve soldier from Jerusalem who served in the military’s Iron Dome antimissile defense unit. He was accused of providing his handler with the locations of Iron Dome batteries and at least seven air bases. He also provided photographs and videos of Iron Dome’s operating procedures and the names of other potential recruits, according to legal documents.

The military also arrested two Israeli conscripts serving as air force technicians who had access to sensitive information about Israel’s planes and radar systems. The two sergeants maintained contact with an agent over Telegram for about a year, according to an indictment served by military prosecutors. They were charged with aiding an enemy.

One of the most sensational and potentially damaging cases of late involved a computer science student from the Haredi community who, with some help from his older brother and AI, is accused of posing as an officer in the military’s vaunted 8200 intelligence unit.

An agent first contacted the student, Meir Nahum, 24, from the Haredi settlement of Beitar Illit, over Telegram in August, according to the indictment in his case. He then set up another profile and began to correspond with the agent in the name of a fictional 8200 officer.

Asked if Israel was involved in the 2024 helicopter crash in which the former president of Iran, Ebrahim Raisi, was killed, Nahum answered in the affirmative. Using ChatGPT, he forged a military document with the 8200 unit’s logo purporting to give more details, according to the indictment and Roi Gavrieli, the police investigator in the case. (Iran blamed the crash on bad weather).

In December, after the handler asked for names of Iranians collaborating with Israel, Mr. Nahum turned to his brother for help.

They found the details of a random Iranian citizen and passed them on to the handler, claiming the man had served as a lookout for an Israeli attack that killed two Iranian military figures last June, according to the indictment and Mr. Gavrieli.

In correspondence later uncovered by the Israeli authorities, the Iranian handler claimed that the citizen identified by the brothers was interrogated, then released and cleared of any suspicion.

The brothers were arrested in January and charged in March. The police said they were paid a total of about 100,000 shekels, or more than $35,000, in digital currency.

“Their sole motivation was money,” Mr. Gavrieli said by telephone. It is unclear if Iranian intelligence fell for the brothers’ scam at any stage, he said. But he added that the claim that Israel was involved in killing President Raisi alone could have prompted revenge attacks or even started a war.

Ariel Atari, a lawyer representing the Nahum brothers, said they don’t deny contact with an Iranian agent, which is a crime, but he disputed the prosecution’s claim that their actions had endangered Israel.

On the contrary, Mr. Atari argued, the brothers helped Israel by “getting money out of the Iranians in return for false information.”

The Israeli authorities do not view it that way. The brothers face another court hearing on Sunday.