iPhone sending text message by itself

I have this problem as well with an iPhone 5, it has also made calls to 3 or 4 different contacts.Sounds like a virus or malware but from what i have read iPhones cant get malware. When I connected the iphone to my PC. The antivirus detected a rootkit.Not sure if it was from the PC or the phone.

There is no known malware capable of infecting any iOS device, unless it has been jailbroken.

Assuming that it hasn't been jailbroken, there are a couple possibilities. One is that someone has hacked your iCloud account. In this case, they can access and modify your contacts and send text messages, and the results of those actions will be synced to your phone. Change your iCloud password.

Another possibility is that something is wrong with the phone. Try the restart and restore steps in the following document:

http://www.apple.com/support/iphone/assistant/phone/

If none of that helps, it may be a hardware issue.

The same thing happened to my brother today. Apparently, if you have someone blocked and someone else tries to send a message to the both of you through SMS or iMessage, the text will go through as MMS to the other person, despite having the other person blocked. This bug will be patched with the next iOS 8.4 update due to arrive in the summer.

I was chatting with my friend on the LINE app, and I saw my phone sent a text message to my friend by itself. Couple years ago, it also made phone calls to people from my contact at 3am.