Google has announced a countermeasure against "Stagefright," a flaw that has been discovered in the search company's Android operating system. The discovery has been made by security firm Zimperium last week. "Stagefright" sends malware to Android users by linking infected videos. The firm said that the videos did not even have to be clicked open for hackers to take over infected devices in some cases. 

The search company has announced that it has rolled out the fix for Nexus phones. On Wednesday, Google emailed NBC News saying 90 percent of Android devices are protected by "address space layout randomization," a programming technique made for the operating system. The company also indicated that its messenger app will be updated to have a feature which will require videos to be clicked before users can play them. 

The fix and update have already been made available to Nexus. Other Android devices will be having them within the month. 

The medium with which videos are sent is the operating system's default messenger app. A preview of the message is enough for hackers to have control over the user's device. "You're sleeping at 2 a.m. You get a message and that's it -- your phone is infected," Zimperium founder Zuk Avraham told NBC News. "You can wake up and not even know it happened. This is a very dangerous flaw." 

Zimperium branded Stagefright the "mother of all Android vulnerabilities", saying it can "critically expose" 95 percent of devices that use the Android operating system. Aside from the Android messenger, Google Hangouts was also tested and found to be vulnerable to the bug.

Big operating systems and websites have been targets of recent hacking incidents. Microsoft's Windows 10 release has been used to spread ransomware on the week of its launch. Yahoo visitors have similarly been victimized by malware, as hackers use the website's ads to make a massive malvertisement campaign. Yahoo, like Google, has been able to counter the malicious attacks.