The email app (Mail) on Apple iPhone could be the opening door for hackers and vulnerable to malware attacks, as reported by The Wall Street Journal.

The report is based upon the claims of cybersecurity company ZecOps Inc. that says that hackers have found a flaw in Mail app on Apple iPhones which have been virtually undetectable by victims for more than two years.

The iPhone can be hacked without you having to click on a link or download any file.

To make such a sneaky attack possible, hackers could send in a "malware without input", which would be in the form of a "specially designed message", claim researchers.

The cybersecurity company says that it couldn't get its hands on the malware in iOS as messages had already been deleted.

The company learned about the hack through hints in iOS. However, the report goes on to say that Apple may have fixed this vulnerability in an iOS beta release. If that is true, Apple may plug this claimed vulnerability soon.