The man was the second teenager arrested in the Netherlands for cyber attacks in the past few days after police detained a 16-year-old youth on Thursday in connection with cyber attacks by WikiLeaks supporters.
The youth, arrested in The Hague, is being held on remand.
The prosecutor's office said on Sunday the 19-year-old man admitted involvement in the so-called denial of service attack against the prosecutor's website.
He also confessed to being involved in cyber attacks against Mastercard, Visa and Moneybookers, the statement added.
Cyber activists around the globe have attacked organizations seen as foes of WikiLeaks in retaliation for the ending of services to the website after it published thousands of secret U.S. diplomatic reports.
Involvement in denial of service attacks carries a maximum prison sentence of six years in the Netherlands.
(Reporting by Aaron Gray-Block; Editing by Jon Hemming)