The NSA is known for its sophisticated surveillance techniques. Hard disks made by companies such as Seagate, Toshiba, Hitachi, Samsung, Maxtor and Western Digital, all of the world’s major hard drive manufacturers, have some spyware code that can be used to remotely monitor these storage devices. That’s what researchers at Kaspersky Lab say Reported. And that’s why researchers have pointed the finger at the NSA.

These malware hidden in the hard drive firmware become active as soon as the computer is turned on. These are not detected by any simple antivirus scanning and even if the hard drive is formatted, it is not possible to remove these malware.

The amount of engineering required to make such an arrangement in the firmware of a device is not insignificant. According to technology analysts, hard drive manufacturers may have helped the NSA to spread the virus. However, many people think that the companies may have been forced to do this.

Reuters contacted the companies concerned to find out what really happened. However, only Western Digital has denied the allegation of sharing their source code with the NSA. Other companies declined to comment.