Apple says it is issuing a security update after powerful espionage software was found targeting an activist's iPhone in the Middle East.

Computer forensics experts tell The Associated Press the spyware takes advantage of three previously undisclosed weaknesses in Apple's mobile operating system to take complete control of iPhone handsets.

Two reports published Thursday by the San Francisco-based Lookout and internet watchdog group Citizen Lab outline how the spyware could compromise an iPhone with the tap of a finger, a trick so coveted in the world of cyberespionage that one spyware broker said last year that it had paid a $1 million dollar bounty to programmers who'd found a way to do it.

Apple said in a statement that it fixed the vulnerability immediately after learning about it.

Information from the Associated Press was used in this report.