U.S. intercepts encrypted Iranian transmission that may activate domestic sleeper cells

U.S. intelligence agencies intercepted an encrypted radio transmission "likely of Iranian origin" relayed across multiple countries that may serve as "an operational trigger" for sleeper assets inside the United States and abroad. The transmission was encoded and appeared to target "clandestine recipients" with an encryption key, bypassing internet and cellular networks. Federal officials issued an alert to domestic law enforcement agencies stressing there was "no operational threat tied to a specific location" but urging heightened situational awareness.