From Heroes Wiki
The CIA logo
The Central Intelligence Agency is a U.S. government agency created in 1947 to collect and correlate foreign intelligence to protect the natural security of the United States of America.
Hana again states that Mr. Bennet told her he was with the CIA.
Hana is captured in Tanzania and tells her captors that she is with the CIA. At the U.S. Embassy, an Embassy employee tells Hana that there is no record of her ever working for the CIA, nor of the Alaskan facility.
In chapter 2 of The Private, one of Rachel Mills's captors in Iran, Harry, informs Rachel that they thought that the CIA was surveilling her, but that now they don't know who was doing the surveillance.