The July 3 cable, first reported by The Washington Post, revealed that the perpetrator created a Signal account under the name “Marco.Rubio@state.gov” and began contacting officials in mid-June. At least two targets received AI-generated voicemails, while others were invited to continue the conversation on Signal. The exact contents of the messages remain unclear.
According to U.S. officials, the impersonator’s goal was likely to extract sensitive information or gain unauthorized access to accounts. The State Department has since launched an internal investigation and issued a warning to all embassies and consulates worldwide.
“There is no direct cyber threat to the department from this campaign, but information shared with a third party could be exposed if targeted individuals are compromised,” the cable stated.
A State Department spokesperson confirmed that the agency is actively monitoring the situation and taking steps to bolster its cybersecurity defenses. The department declined to share further details, citing security concerns.
Officials say this incident is part of a broader disinformation campaign. A second operation, believed to be linked to Russian actors, began in April and targeted Gmail accounts of journalists, activists, and former government officials, using a fake State Department identity. The FBI has also issued public warnings about a growing trend of “smishing” (SMS phishing) and “vishing” (voice phishing) attacks using AI-generated content. The bureau says malicious actors have begun impersonating senior U.S. officials to deceive associates and gain trust. This isn’t the first time Rubio has been targeted. Earlier this year, a deepfake video falsely claimed he wanted to cut off Ukraine’s access to Starlink. Experts say such incidents are becoming harder to detect as AI-generated content grows increasingly realistic.
“It’s an arms race,” said Siwei Lyu, a computer science professor at the University at Buffalo. “AI deepfakes are improving rapidly, and the tools to detect them are struggling to keep up.”
The Rubio impersonation follows a similar breach involving Trump Chief of Staff Susie Wiles, whose contacts received AI-cloned calls and messages in May. Authorities are investigating whether those behind that breach also accessed Wiles’ personal phone data.
As the threat of deepfake deception escalates, experts and lawmakers are calling for stricter regulations, criminal penalties, and new detection technologies to counter the misuse of generative AI.
