It's a major blow against criminals using Tor - but security experts don't know how law enforcement agencies cracked the once-anonymous network

A massive cybercrime operation carried out by Europol and US law enforcement has shut down hundreds of illegal sites operating on the anonymous Tor network.

Reports yesterday suggested that the main target was the site Silk Road 2.0 - the successor to the notorious ‘eBay for Drugs’ which was shut down last October - but new details have revealed the scope of the sting.  

‘Operation Onymous’ (a not-so subtle dig at the hackers and cyber-criminals running the sites: ‘onymous’ means ‘named’) is believed to be one of the largest ever targeted at the ‘dark net’ with 414 sites shut down, 17 individuals arrested (including six in the UK) and millions of dollars’ worth of bitcoins and drugs seized.

The sites were operating using the Tor network, a technology that allows users to hide their activities online by bouncing their connections around multiple relays.

It was originally developed by the US Navy to secure military communications and is used legitimately by journalists and activists – especially in countries were online activity is heavily monitored like China and Iran.

However, it’s also home to a number of illegal market places for drugs, weaponry, child abuse material and money laundering.

‘Operation Onymous’ suggests that Tor and the dark net is no longer the safe haven for criminals that it was once thought to be, although the small ratio of arrests to sites close suggest that whatever methods law enforcement are using to track down criminals, they’re still not as effective as those used to police the regular web.

"Today we have demonstrated that, together, we are able to efficiently remove vital criminal infrastructures that are supporting serious organised crime," said Troels Oerting, head of Europol's European cybercrime centre.

He continued: "And we are not 'just' removing these services from the open internet; this time we have also hit services on the dark net using Tor where, for a long time, criminals have considered themselves beyond reach.”