US Warns Iran Sent Encrypted Signal to Activate Sleeper Cells Abroad

U.S. officials issued a federal alert after intercepting encrypted communications they believe likely originated in Iran and could function as an "operational trigger" to activate sleeper assets abroad.

“Iran may be activating sleeper cells outside the country, alert says The encrypted transmission was intercepted by the U”

ABC News

The alert, reviewed by ABC News, described preliminary signals analysis indicating the transmission may have been relayed across multiple countries and flagged it as potentially intended to mobilize prepositioned cells.

ABC News

Officials characterized the intelligence as preliminary and unverified, prompting heightened concern among law enforcement and intelligence communities.

According to the alert, the transmission was relayed internationally shortly after the reported death of Iran’s Supreme Leader Ayatollah Ali Khamenei on Feb. 28.

The notice attributes that death to a U.S.-Israeli attack and cites the timing as part of the rationale that the signal could serve as a trigger.

Fox News

Both ABC and the New York Post emphasize that the exact content of the broadcasts remains unknown.

U.S. officials describe the intelligence as preliminary and unverified.

A government notice asked law enforcement to increase monitoring of suspicious frequencies and raised situational awareness, while officials said there were no specific, credible threats to the public.

“The United States is raising a warning about the possible activation of Iranian sleeper cells abroad”

lamilano.it

Counterintelligence experts cited in reporting warned of potential revenge or inspired attacks tied to the wider conflict, and U.S. counterterrorism and intelligence teams were reported to be on high alert in response to the memo.

Investigators are probing whether a recent mass shooting in Austin — where the suspect reportedly wore an Iranian-flag shirt — was motivated by the conflict.

Senior officials, including FBI Director Kash Patel, described counterterrorism and intelligence teams as working around the clock.

New York Post

Both outlets emphasized the preliminary nature of the intelligence and said there is significant uncertainty about the broadcasts' origin, intent, and any operational link to incidents on U.S. soil.