A hacker associated with a Mexican cartel utilized an FBI agent’s phone records and public surveillance cameras to locate, intimidate, and even eliminate government informants, as detailed in a recent report.

This hacker, employed by the notorious Sinaloa cartel under Joaquín “El Chapo” Guzmán, infiltrated the phone of an FBI assistant legal attaché based at the US Embassy in Mexico City. Through this breach, the hacker acquired a significant amount of information that guided the criminals directly to government informants.

The specific timeline of the hacking incident remains unknown, as well as its duration, but it was unveiled during a recent FBI audit focused on enhancing the bureau’s defenses against emerging technological threats, as reported by Reuters.

The hacker was able to break into the agent’s phone remotely and watch their incoming and outgoing calls, and even monitor the phone’s geolocation, according to the report.

Once armed with that data, the hacker gained access to Mexico City’s street surveillance cameras to follow the FBI agent to see who they were meeting with.

“The cartel used that information to intimidate and, in some instances, kill potential sources or cooperating witnesses,” the report read.

It remains unclear how many informants were compromised by the hacking operation, or who the FBI agent at the center of it was.

The identity of the hacker also remains unclear.

Public surveillance infrastructure coupled with cellular data has made it increasingly difficult to carry out covert operations abroad, especially for agents who depend on informants to access their targets.

New technologies “have made it easier than ever for less-sophisticated nations and criminal enterprises to identify and exploit vulnerabilities,” the report read.

El Chapo remains imprisoned in the US after being arrested and extradited in 2017.