WhatsApp, a Facebook-owned messaging service, is very populatr: the total number of its users is about 1.5 billion people. Recently a serious vulnerability was found in it, which enabled hackers to install spyware on the victims’ devices by means of an infected voice call in WhatsApp.

Even if users didn’t answer that call, they could fall victim to the attack anyway. What’s more, these calls were often hidden from the logs.

The spyware is said to be capable of performing various malicious activities: it can activate the camera and microphone of the phone, trawl through the data, etc.

Facebook already implemented a server-side change as well as pushed out updates for a variety of smartphone WhatsApp versions, in order to protect WhatsApp users.

The number of victims isn’t known exactly yet. What is known is that all users having WhatsApp or WhatsApp Business apps installed could be affected. According to Facebook, all brands of phones proved to be vulnerable, including Android phones, Tizen devices, iPhones, and Windows Phones.

In view of this, all users are strongly recommended to check the version of their WhatsApp apps and update them on their iOS, Android or Windows devices. You should do it as soon as possible, especially if you remember receiving any WhatsApp voice calls from unknown parties or dropped calls. Keeping your device updated at all times is crucial.