WASHINGTON, 25 April — US Defence Secretary Pete Hegseth had an unsecured internet connection, known as a “dirty” line, installed in his Pentagon office to use the Signal messaging app on a personal computer, according to two sources familiar with the matter.
This revelation adds to growing concerns about Hegseth’s handling of sensitive defence information and potential security vulnerabilities at the highest levels of the Department of Defence.
The Associated Press reported that the unsecured connection bypassed Pentagon security protocols and could have exposed sensitive information to potential hacking or surveillance threats.
Unlike standard Pentagon connections that employ robust security filters and protocols, a “dirty” line connects directly to the public internet without these protections.
While such connections are occasionally used in other Pentagon offices for specific monitoring purposes, they come with significant security risks.
One major advantage of using such a line is that it masks the user’s identity, preventing them from appearing as a Department of Defence IP address, according to a senior US official familiar with military network security.
However, this setup potentially lacks the record-keeping compliance required by federal law and exposes users to the same security vulnerabilities as any public internet connection.
The unsecured connection was reportedly installed specifically for Hegseth to use the Signal messaging app, which has become a central focus of controversy following revelations that he shared sensitive details about a military airstrike in Yemen against Houthi militants.
The information was posted in two separate chat groups: one including his wife and brother, and another with President Donald Trump’s top national security officials.
When questioned about Hegseth’s Signal use in his office, Pentagon spokesman Sean Parnell stated that the defence secretary’s “use of communications systems and channels is classified.”
However, Parnell confirmed that “the Secretary has never used and does not currently use Signal on his government computer,” suggesting the app may have been accessed through his personal device connected to the unsecured line.
The Pentagon provides several secure communication options for high-ranking officials like Hegseth, including the Non-classified Internet Protocol Router Network for low-level sensitive information, the Secure Internet Protocol Router Network for secret-level classified information, and the Joint Worldwide Intelligence Communications System for top-secret information.
Sources reported that Hegseth initially accessed Wi-Fi from a back area of his office before requesting a direct line at his desk for his personal computer.
The security breach has added to the turmoil at the Pentagon, where Hegseth has already dismissed or transferred multiple close advisers while facing bipartisan questioning about his information handling practices.
Despite these concerns, President Trump and his administration have continued to express full support for Hegseth, with Trump dismissing the reports as “fake news” and Vice President JD Vance stating, “I have 100 per cent confidence in the secretary.”
Cybersecurity experts stressed that while Signal offers encrypted messaging, it is not authorised for handling sensitive or classified information and remains vulnerable to sophisticated hacking attempts.
Theresa Payton, former White House chief information officer under President George W. Bush, warned that communications of senior government officials are prime targets for adversaries like Russia and China.
Earlier this year, the National Security Agency issued warnings about foreign hackers potentially targeting government officials using Signal.
The Department of Defence’s acting inspector general is now investigating Hegseth’s use of Signal at the request of bipartisan leadership from the Senate Armed Services Committee.
The investigation centres on Hegseth pulling information about a Yemen strike from a secure US Central Command channel and sharing details such as exact launch times and bomb drop times before pilots had safely returned from their mission.
Although Hegseth has vehemently denied posting “war plans” or classified information, multiple current and former military and defence officials have stated that the operational details he shared would have been classified and could have endangered service members.