A former staff member who worked in an office of a United States Senator pled guilty Friday to federal charges stemming from his theft of Senate information and the illegal posting of restricted personal information of five U.S. Senators, as well as related conduct.
Jackson A. Cosko, 27, of Washington, D.C., pled guilty to five federal offenses: Two counts of making public restricted personal information; one count of computer fraud; one count of witness tampering, and one count of obstruction of justice.
Under federal sentencing guidelines, Cosko could face a prison term 30 to 57 months. The plea agreement requires Cosko to forfeit computers, cellphones and other equipment used in the crimes.
Senior Judge Thomas F. Hogan scheduled sentencing for June 13.
U.S. Capitol Police began an investigation on Sept. 27 last year, after it was determined the Wikipedia pages of three U.S. Senators had been edited to include restricted personal information without their knowledge or permission, according to Department of Justice (DoJ) officials.
The information included home addresses and personal telephone numbers. These edits took place roughly contemporaneously with the highly publicized Senate proceedings related to the nomination of U.S. Supreme Court Justice Brett Kavanaugh. Then, on Oct. 1, 2018, similar information was posted on the Wikipedia pages of two additional Senators.
“Doxxing” is the act of gathering, by licit and illicit means, and posting on the Internet personal identifying information (“PII”) and other sensitive information about an individual.
In a statement, Cosko admitted he had been angry about his termination in May 2018 from his employment as a computer systems administrator in the office of another U.S. Senator, Sen. Maggie Hassan, D-NH.
As a result, beginning no later than July 2018 and continuing until October 2018, he engaged in an extensive computer fraud and data theft scheme. He admitted he carried out the scheme by breaking into Senator Hassan’s office on at least four occasions and accessing Senate-owned computers for the express purpose of stealing proprietary electronic information, including the personal contact information for other Senators. He then published the contact information for five U.S. Senators using Wikipedia and Twitter.
It all started to unravel for Cosko on the night of Oct. 2, according to the evidence, That is when a witness saw Cosko at a computer in Hassan’s office. The witness confronted Cosko, who left the office. Later that evening, according to the statement of offense, Cosko sent a threatening email to the witness, titling it, “I own EVERYTHING” and warned, “If you tell anyone I will leak it all.” Additionally, that evening Cosko attempted to delete electronic evidence from items including a laptop computer that he used to obtain and download the stolen data.