Ahead of the November 3 midterm elections, the FBI and the Cybersecurity and Infrastructure Security Agency (CISA) issued a joint advisory urging election officials, candidates, and the public to remain alert to AI-driven cyber threats, noting that deceptive phishing emails and text messages could be used to extract sensitive data.

A Friday notice from the agencies flagged phishing attempts targeting candidates, election officials, and affiliated political organisations, identifying those groups as particularly sought after by threat actors aiming to obtain account credentials and other sensitive data through deceptive digital communications. The document also noted that developments in AI technology have the potential to make phishing attempts harder to detect.

The alert contained the term "super intelligence" — a phrase linked to President Donald Trump — and noted that online fraudsters had begun exploiting the technology to produce phishing emails and text messages that appeared more authentic, a news outlet reported.

The alert has emerged against the backdrop of an unrelated inquiry into packages of a questionable nature delivered to election officials and legislators before the midterm votes. Two federal agencies — the FBI and the US Postal Inspection Service, which operates as the law enforcement branch of the US Postal Service — announced Thursday that correspondence directed at state election officials and legislative offices had come under investigation. A handful of the envelopes were found to hold a powder or material that investigators had yet to identify.

The inquiry falls at a notable point on the political calendar, with the November 3 vote — the one that will determine congressional control — arriving in under three weeks. Handling of absentee ballots, expected to arrive by the millions, forms part of the agency's current operational planning.

Representatives for Senate Democratic Leader Chuck Schumer and Democratic senators Alex Padilla of California and Chris Murphy of Connecticut confirmed that the Postal Service had intercepted envelopes containing an unidentified substance before they reached the lawmakers' offices, according to a broadcast news outlet. In a written statement, Padilla noted that the episode underscored the genuine risks faced by those in public service roles and those involved in overseeing elections.

A notice distributed to House staff by the chamber's top law enforcement officer — the sergeant at arms — disclosed that envelopes carrying an unidentified white powder had been delivered to a number of public officials.

Brendan Donahue, a deputy chief inspector with the US Postal Inspection Service, confirmed that a number of letters deemed suspicious had been intercepted and that the inquiry remained active, adding that the agency was focused on keeping election officials across the country safe from threatening correspondence sent through the mail. Donahue told reporters that no form of threat or violence directed at an election official could be considered acceptable.

Two election-administration bodies — the National Association of Secretaries of State and the National Association of State Election Directors — disclosed on Wednesday that an unspecified number of questionable letters had arrived at offices responsible for overseeing elections across the country. Mail bound for election administration offices in Pennsylvania, Ohio, and Idaho was intercepted before delivery, a news outlet reported.