Police have raided homes in five European countries as part of a malware investigation, according to agency reports.
Officers in the UK, Germany, France, Belgium and Switzerland raided several properties connected to suspected users of malware known as DroidJack.
DroidJack allows criminals to spy on smartphone data traffic, eavesdrop on conversations and hijack the camera.
The suspects were aged between 19 and 51. No arrests have yet been reported.
The raids were reported by the AFP and Reuters news agencies while Europol also say that searches were conducted in the United States.
Britain’s National Crime Agency was not able to confirm any details of the UK operation.
A total of 13 homes in Germany and one in Switzerland were raided, the news agencies said.
DroidJack is a remote access trojan or “Rat”, which is openly sold online for $210 (£137), affects Android devices only.
‘Every move’ tracked
“It can track a user’s every move without their knowledge,” explained Peter Coogan, principal security response manager at Symantec.
“There was a documented case back in 2014. I think where it was being sent out via spam email and pretending to be a bank. It is likely at that time that they were trying to steal banking details off the phone,” he told the BBC.
Mr Coogan added that he has tracked discussion of the malware on underground hacking forums where DroidJack has been marketed.
“More people will have purchased it and are probably using it,” he said.