The US Department of Defense has spent more than a year studying a portable device obtained in a covert purchase that investigators believe may be capable of reproducing symptoms reported by personnel affected by “Havana syndrome”.

CBS News reported that the US government acquired the device in late 2024. Two people familiar with the matter told CBS it was bought clandestinely by Homeland Security Investigations (HSI), a division of the Department of Homeland Security, using Pentagon funding that exceeded eight figures.

According to those accounts, the device is portable and can be carried in a backpack. Investigators said it emits pulses of radio-frequency energy and contains components of Russian origin, though sources cited by CNN and CBS described it as not entirely Russian-made.

The equipment remains under study and there is no settled US government position that it explains the incidents grouped under the label “Havana syndrome”. A CNN Newsource summary said there was still disagreement about whether the device was responsible for the unexplained illnesses.

“Havana syndrome” is a colloquial term for a set of symptoms first reported by US diplomats and intelligence personnel in Havana, Cuba, in 2016, and later reported in other countries. Victims have described neurological and sensory symptoms including severe headaches, head pressure, vertigo, nausea, and ringing or popping sensations in the ears. Some reported hearing an intense sound that appeared to stop when they moved location.

US government figures cited by CBS put the number of reported cases at more than 1,500 since 2016. The Biden administration formally used the term “Anomalous Health Incidents” (AHIs) for the reported events.

The new reporting sits alongside earlier intelligence community assessments that largely discounted the likelihood of a foreign-directed weapon campaign. An unclassified Intelligence Community Assessment updated as of December 2024 and released in January 2025 stated that “most” of the intelligence community continued to assess it was “very unlikely” a foreign adversary was responsible for events reported as possible AHIs.

That document set out a split: five intelligence community components judged it “very unlikely” a foreign actor was responsible, while two components assessed there was a “roughly even chance” that a foreign actor either used, or developed, a novel weapon or prototype device that could have harmed a small subset of personnel. The assessment said both of those latter judgements were held with “low confidence”.

The same assessment discussed the feasibility of a deliberate mechanism such as pulsed radio-frequency energy, while stating that intelligence reporting and investigations had not linked a foreign actor to any specific incident. It also said medical research did not indicate a consistent set of physical injuries across those reporting possible AHIs.

Parallel to official assessments, media investigations have periodically argued for a Russian link. In March 2024, an investigation by The Insider, Der Spiegel and CBS’s 60 Minutes suggested connections between incidents and Russia’s GRU Unit 29155, which has been linked in open reporting to overseas sabotage operations; Russia has rejected responsibility.

The legal and welfare framework for affected personnel has developed in the absence of a definitive cause. The HAVANA Act, signed in October 2021, authorised US agencies to make payments to covered employees and dependants for qualifying brain injuries associated with such incidents.

For defence and security planners, the core operational issue raised by the reported acquisition is portability. A device described as backpack-sized and emitting pulsed radio-frequency energy would, if proven capable of producing the reported effects, imply a threat model that differs from conventional surveillance and harassment risks around diplomatic facilities. US broadcasters carrying the CNN material said officials were seeking to determine whether other countries had access to the same technology or similar devices.

No technical findings from Pentagon testing have been made public, and key agencies have been cautious in public comment. CBS reported that the Pentagon and DHS did not immediately reply to requests for comment, and that the CIA declined to comment.