More than 26,000 people have downloaded an operating system which members of the Anonymous hacker group claim to have created.
The software is based on a version of the open-source operating system Linux and comes outfitted with lots of website sniffing and security tools.
The "official" Anonymous group has distanced itself from the software.
In a widely circulated tweet, AnonOps claimed the operating system was riddled with viruses.
The operating system is available via the Source Forge website a well-known repository for many custom code projects.
The 1.5GB download is based on Ubuntu - one of the most popular versions of the Linux operating system. The software's creators say they put it together for "education purposes to checking the security of web pages (sic)".
It asked people not to use it to destroy webpages.
Soon after the operating system became available, the AnonOps account on Twitter posted a message saying it was fake and "wrapped in trojans".
The creators of the OS denied it was infected with viruses adding that, in the world of open-source software, "there were no viruses".
After downloading and running the software, Rik Ferguson, director of Trend Micro's European security research efforts, said it was "a functional OS with a bunch of pre-installed tools that can be used for things like looking for [database] vulnerabilities or password cracking".
It also included tools such as Tor that can mask a person's online activities. In many ways, he said, it was a pale imitation of a version of Linux known as Back Track that also comes with many security tools already installed.
Mr Ferguson said he was starting work to find out if there were any viruses or booby-traps buried in the code.
Graham Cluley, senior researcher at hi-tech security firm Sophos, wondered who would be tempted to use it.
"Who would want to put their trust in a piece of unknown software written by unknown people on a webpage that they don't know is safe or not?" he asked.
He warned people to be very wary, adding that some hacktivists keen to support the work of Anonymous had been tricked earlier in the year into installing a booby-trapped attack tool.
"Folks would be wise to be very cautious," he said.