The U.S. Federal Bureau of Investigation (FBI) confirmed on Thursday that it's investigating a breach that affected systems used to manage surveillance and wiretap warrants. While the federal law enforcement agency declined to share more details regarding the incident's scope and overall impact, it said that the incident has already been addressed. "The FBI identified and addressed suspicious activities on FBI networks, and we have leveraged all technical capabilities to respond," the law enforcement agency told BleepingComputer, but declined to provide additional information. On Thursday, CNN, which first reported the incident, cited an anonymous source saying the breach affected FBI systems used to manage wiretapping and foreign intelligence surveillance warrants. While it's unclear at…