According to a report in Vice magazine, the 2015 FBI investigation Operation Pacifier involved investigators taking over a child pornography site and infecting the computers of visitors to the site with a piece of malware that grabbed their IP address.
Around 1000 computers around the world were affected and Vice has now revealed that 50 computers based in Austria were also compromised. According to the magazine, it was the first time the FBI have hacked computers in Austria.
A letter written to Austrian MPs in March 2016 by the then Austrian Interior Minister Johanna Mikl-Leitner confirmed there was 'international collaboration' between Europol and Operation Pacifer.
She added that the 50 IP addresses revealed as a result of the operation were analysed by the federal intelligence office and led Austrian prosecutors to “countless child pornography files.”
A spokesperson for the Austrian office told the Kurier newspaper this week: “We received the IP addresses transmitted in an FBI report. The whole thing was very successful, each one was a hit.”
It is unclear if the cases involving the 50 IP addresses are currently being dealt with by the Austrian judiciary.
The legality of the mass hacking of foreign computers carried out by Operation Pacifer is being brought into question by some lawyer in the US.
They argue that the warrant issued for the hacking was unconstitutional and the judge who issued it did not have authority to give the go ahead for searches outside of her own district.
“The dramatic expansion of the FBI's extraterritorial reach raises serious questions,” Scarlet Kim, a legal officer from activist group Privacy International, told Vice.