An international police investigation into the trade of illicit items on the dark web has culminated in two of the biggest dark web marketplaces - AlphaBay and Hansa - being shut down.
The takedown follows months of preparation and coordination from law enforcement in the US and Europe, led by the Federal Bureau of Investigation (FBI), the US Drug Enforcement Agency (DEA) and the Dutch National Police, with the support of Europol, the European Union’s law enforcement agency.
Europol said the shutdown will lead to “hundreds” of new investigations in Europe.
The AlphaBay and Hansa sites had been associated with the trade of illicit items such as drugs, weapons, malware and stolen data. There were more than 250,000 listings for illegal drugs and toxic chemicals on AlphaBay, according to Europol.
What's more, there were over 100,000 listings for stolen and fraudulent identification documents and access devices, counterfeit goods, malware and other computer hacking tools, firearms, and fraudulent services, the agency said.
The agency believes an estimated $1bn was transacted in the market since its creation in 2014.
Hansa was the "third largest criminal marketplace on the dark web", the agency said, trading similarly high volumes in illicit drugs and other commodities.
The marketplaces use online currency Bitcoin to trade the goods, an anonymous currency that is virtually untraceable.
Bitcoin is also adopted by online hackers in ransomware attacks. This was most recently highlighted in the cyber attack against agency holding group WPP, where files were taken hostage for a $300 Bitcoin fee.
AlphaBay went offline on 5 July, when law enforcement arrested the creator and administrator of AlphaBay, a Canadian citizen living a "luxurious" life in Thailand.
But when one marketplace goes offline, that doesn't stop the trade of illegal items - instead those users migrate to a different site. In this instance, users of AlphaBay took to online forums like 4chan to discuss potential alternative dark web marketplaces, when Hansa's name was mentioned. Authorities tracking the online forums could have used this as a tip off to detect new criminal activity on Hansa.
The Dutch National Police took over the Hansa marketplace on 20 June after two men in Germany were arrested and servers in Germany, The Netherlands and Lithuania were seized. This allowed for "the covert monitoring of criminal activities on the platform" until it was eventually shut down a month later.
Europol said the coordinated law enforcement action in Europe and the US makes it "one of the most sophisticated takedown operations ever seen in the fight against criminal activities online".
Rob Wainwright, the executive director of Europol, said at a special press conference in Washington DC that the capability of drug traffickers and other serious criminals around the world has "taken a serious hit today" after a "highly sophisticated" joint action in multiple countries.
"By acting together on a global basis the law enforcement community has sent a clear message that we have the means to identify criminality and strike back, even in areas of the dark web. There are more of these operations to come," he added.