Spanish Police Arrest 16-Year-Old Accused of Running KillSec Ransomware Group

Spanish police have arrested a 16-year-old suspected of being the main operator of the KillSec ransomware group, as law enforcement across Europe seized its servers and leak site and secured at least 110 terabytes of stolen data, Europol said. The teenager, a Romanian national detained in Alicante, is suspected of acting as the group's administrator, a Europol spokesperson told Reuters. Two other people in their twenties were arrested, one in Britain and one in Romania. A fourth suspect, a developer who turned 18 in August and was a minor when some of the offences were committed, has been identified but not arrested. The September 30 action was part of Operation KillSwitch, an investigation led by the Hamburg State Criminal Police Office and the city's public prosecutor into around 1,000 suspected attacks worldwide, of which about 500 have so far been identified as successful. Eight properties were searched in Spain, Greece, Romania and the UK. The man held in Britain faces charges in the U.S. Fouad Eltibrizi, a Dutch national resident in the UK who used the handle Archduke, was indicted by a federal grand jury in Puerto Rico on September 16 over conspiracy to access computers without authorization for financial gain, damaging protected computers and transmitting extortion threats. He was arrested the following fortnight and faces extradition, with a maximum penalty of 10 years. Today we’re announcing Operation KillSwitch, a joint sequenced operation led by @FBISanJuan targeting the Kill Security Ransomware Group (“KillSec”). Authorities in the U.S. and Europe took control of KillSec’s leak site, securing at least 110 terabytes of data against further… pic.twitter.com/ZYvxosEPyv — FBI Cyber Division (@FBICyberDiv) October 1, 2026 U.S. prosecutors say KillSec posted a Puerto Rico breach on its leak site in March 2025 with samples of stolen patient data and a seven-day countdown. When the company did not respond, roughly 180GB were published. The indictment de