Indian defence forces see pen drives as major threat to their cyber security the use of pen drives has been found responsible for more than 70 per cent cyber security breaches in the three Services.

Army officials said that the use of easy-to-carry pen drives for storing data had increased over the recent past, despite a ban on their use in the services.

Speaking on the condition of anonymity, the officials said, "These pen drives, which are mostly manufactured in China, have emerged as a big threat to our cyber security systems."

Sources cited some incidents in which some officials were found using pen drive to store official data for using that data at their PCs, but the `malware' present in the pen drives sent that data from PCs to hackers.

The Army headquarters have recently issued fresh cyber security guidelines to prevent potential hackers' attacks on sensitive military networks. Indian Air Force (IAF) and Navy have also issued instructions to their officials warning them against using pen drives to shift any official data to their PCs.

When contacted, IAF spokesperson Wg Cdr Gerard Galway said fresh guidelines were issued to safeguard Air Force's cyber assets and confidential data.

Meanwhile, the National Security Council (NSC) is mulling over a plan to designate certain intelligence agency under the Defence Ministry to counter cyber offensives against the nation.