Images of child sexual abuse and stolen credit card numbers are being openly traded on encrypted apps, a BBC investigation has found. Security experts have said that the encrypted apps were taking over from the dark web as a venue for crime.
The secure messaging apps, including Telegram and Discord, have become popular following successful police operations against criminal markets operating on what is known as the dark web – a network that can only be accessed by special browsers.
The secure apps have both a public and encrypted side.
Often, the public side is listed online so users can search and join groups advertising drugs, stolen financial data and other illegal material.
Once a group is joined, however, messages are protected by peer-to-peer encryption, generally putting them beyond law enforcement’s reach, say experts.
The investigators found evidence that paedophiles were using both Telegram and Discord to give people access to abuse material, and that links to Telegram groups were buried in the public comments section of YouTube videos.
These contained code words that would be indexed by search engines and, once clicked on, took people to the closed group.
Researchers confirmed that at least one of these groups contained hundreds of indecent images of children.
The BBC investigation also found that paedophiles are exploiting the Discord app, which is popular among young people, who use it to text and chat while gaming online.
It discovered a series of chatrooms openly promoted as suitable for 13 to 17-year-olds, but with very sexual descriptions that aimed to persuade children to hand over explicit photos.
Ariel Ainhoren, head of research at security firm IntSights, said the firm had recently identified a group on Discord in which one user had posted a price list for child abuse imagery. The group was no longer active, but the user had given out an email address for sales queries that was still viewable online.
“The user was offering gigabytes of pornography or paedophile material: nine gigabytes for $50 (£39), 50 gigabytes for $500, and 2.2 terabytes, which is a huge amount, for around $2,500,” said Mr Ainhoren.
Nine gigabytes could contain many thousands of images, depending on the file sizes.
The user also said he was selling access to child sexual abuse and rape forums.
File on 4 has passed details of the illegal material revealed by its investigation to the National Crime Agency.
Once told about the groups, Discord said: “The number of these violations makes up a tiny percentage of usage on Discord and the team is committed to improving our policies and processes to make it even smaller.
“Discord’s Trust and Safety policy exists to proactively protect the safety of our users – on and off platform – and we have a variety of security methods that help users avoid unwanted or unknown contact.
“As all conversations are opt-in, we urge users to only chat with or accept invitations from individuals they already know.”
It said it uses computer, human and community intelligence to spot violations of its rules.