U.S. Intercepts Iran Message Activating Sleeper Cells After U.S.-Israel Strike Kills Khamenei

U.S. agencies intercepted an encrypted radio-frequency transmission that preliminary analysis judged 'likely of Iranian origin'.

“The intercepted transmission was encoded and appeared to be destined for "clandestine recipients" who possess the encryption key, the kind of message intended to impart instructions to "covert operatives or sleeper assets" without the use of the internet or cellular networks”

ABC

A federal alert reviewed by ABC News said the transmission was rebroadcast across multiple countries shortly after the reported death of Iran’s supreme leader, Ayatollah Ali Khamenei.

ABC

The alert described the message as a possible 'operational trigger' meant to activate or instruct covert or prepositioned 'sleeper' assets abroad.

The characterization raised concern among U.S. and allied security services about potential retaliatory operations.

Several outlets reporting on the alert framed it as tied to the spike in hostilities following the Feb. 28 strike attributed to the U.S. and Israel.

The circulated alert described the signal as encoded for "clandestine recipients" who would possess the required decryption key.

The alert said the signal was sent without using internet or cellular networks.

ABC News

The alert said it was relayed via a newly observed station with "international rebroadcast characteristics".

Authorities were told there was no specific, location-tied operational threat identified in the notice.

Agencies were directed to heighten monitoring of suspicious radio-frequency activity and increase situational awareness while analysts attempt to determine whether the broadcasts contain operational directives.

Reporting placed the intercept in a broader escalation that followed the Feb. 28 U.S.-Israeli strike, which many articles link to the reported death of Khamenei.

“A federal government alert had been sent to law enforcement agencies, ABC News said”

London Evening Standard

Some outlets described the strikes and their aftermath as producing an expanded theatre of conflict.

Other reporting noted prior U.S. advisories and concerns about Iran-linked sleeper cells in Europe and elsewhere, while regional arrests and seizures in places like Qatar have been cited as part of the wider security picture.

U.S. and allied officials responded with heightened vigilance amid worries about possible revenge attacks and covert operations.

Reports said law-enforcement agencies were warned to increase monitoring of suspicious radio traffic, counterintelligence officials flagged the potential for retaliatory strikes in Western countries, and political figures and security commentators publicly urged caution even as agencies refrained from confirming a specific, actionable plot.

New York Post

Significant uncertainties remain: officials and reports repeatedly note the intercept has not yielded deciphered content, no specific operational target or location has been identified, and some outlets flagged that reporting around Khamenei’s death and the attribution of strikes varies in language and verification.

“Iran sent out a possible “operational trigger” to activate “sleeper assets” abroad after the war with America and Israel began, according to an encrypted message intercepted by the US”

New York Post

The alert therefore raised situational awareness rather than a confirmed imminent threat, and analysts continue to assess whether the broadcasts contain commands or are non-operational transmissions.

News18