Microsoft has warned its Microsoft Word users that they they should not open files with .rtf extension because hackers have found a vulnerability in this file extension for Microsoft Word and are exploiting it.
Microsoft has further said that as of yet no fix is available for this and it is currently working on a solution to this.
Therefore, presently to ensure that your computer does not get affected, stay away from opening files ending with .rtf extension.
A hacker can get full control of your computer if he can manage to get you open an infected .rtf file. Which means that you computer may become part of a botnet where hacker can use it for all kinds of illegal things ranging from spam to fraud and spread of virus.
The hack also works in the preview mode where you open it inside email.
Microsoft has recommended that all .rtf files should be blocked until a fix is release. It has in the meantime released a free tool to block .rtf files on your computer.
RTF stands for rich text format. It is not the default file format for Microsoft Word software but many users use this file format. And Microsoft Word can open this file format.