An Italian alleged to have concealed a Trojan horse program within a chat application that was uploaded to a popular downloads Web site has been arrested by authorities in Milan. Fraud investigators in Milan said Friday that a 26-year-old Sicilian had been arrested under an Italian law concerning the distribution of "malware" following a "virtual pursuit". Investigators warned that the Trojan horse program had been hidden within a chat program called Chat 1on1 and uploaded to the Web portal Supereva, which belongs to Italian ISP Dada. The malicious software has since been removed following a Milanese court order. The program is believed to allow a malicious user to take control over a victim's computer system. Italian police suggest that it could have been used to steal passwords, credit card information and even launch a distributed denial of service attack. This type of attack bombards a target with a tidal wave of fake traffic and was used in February to bring down global Web sites. ZDNet Italy's Alberto D'Ottavi contributed to this report. Take me to the Hackers News Special What do you think? Tell the Mailroom. And read what others have said.