Twin brothers from Springfield have pleaded guilty in federal court in Alexandria to a series of computer hacking schemes that involved stealing credit card information, breaking into State Department computers and obtaining data from a private company.

Muneeb and Sohaib Akhter, 23, admitted during a hearing Friday that they used their positions as government contractors to carry out some of the intrusions and one of the brothers attempted to thwart the investigation into their crimes, according to the U.S. Attorney’s Office for the Eastern District of Virginia.

The brothers were once up-and-coming computer whizzes who, at just 19, were highlighted in 2011 for being the youngest graduates from George Mason University that year. Later, they received a $200,000 research grant from the Defense Advanced Research Project Agency.

In one of the schemes, Muneeb Akhter hacked into the Web site of a cosmetics company in March 2014 and stole thousands of its customers’ credit card numbers and other personal information, according to the U.S. Attorney’s Office. The Akhters and others then used the data to buy flights, hotel stays and attend conferences.

In another scheme, prosecutors said Sohaib Akhter used his contract position with the State Department’s Bureau of Consular Affairs to access passport data belonging to dozens of co-workers, acquaintances and the federal agent investigating his case in February 2015.

When Sohaib Akhter learned he was being transferred from that position, the brothers conspired to install an electronic device behind a wall at a State Department building in order to maintain access to the department’s computer systems, according to the U.S. Attorney’s Office. However, Sohaib Akhter broke the device as he was trying to install it.

Prosecutors said Sohaib Akhter told a co-conspirator he carried out the scheme so he could approve visas and create passports and visas in exchange for payment.

Muneeb Akhter also hacked into a database at a Rockville company where he was working in November 2013, according to the U.S. Attorney’s Office. His goal was to gain information on federal contracts that would help the brothers win contracts for their own technology company.

The Akhters pleaded guilty to charges of conspiracy to commit wire fraud, conspiracy to access a protected computer without authorization and conspiracy to access a government computer without authorization. Muneeb Akhter also pleaded guilty to accessing a protected computer without authorization, making a false statement and obstructing justice.

Muneeb and Sohaib Akhter face up to 50 and 30 years in jail, respectively.