"It has been observed that Indian cyberspace traditionally comes under attack by adversaries on dates of national importance such as 15th August ... In the current year August 15 is falling on Friday, followed by a 2-3 days break. It is possible that an adversary may try and take advantage of these circumstances," National Critical Information Infrastructure Protection Centre (NCIIPC) said in an advisory.
The centre has been created to handle cyber security of critical infrastructure such as defence, power, banks and railways, in the country. Almost entire key infrastructure is using computer and Internet.
The centre has asked government departments and companies to review authorisation issued by them for remote access of their system and update softwares in the system.
"In case of a successful compromise or defacement, it is strongly recommended that compromised or defaced system be examined to determine methodology employed by the attacker. These vulnerabilities must be closed before the back-up system is brought online," the advisory said.
Indian Computer Emergency Response Team has reported 13,301, 22,060, 71,780 and 62,189 security incidents in 2011, 2012, 2013 and 2014 (till May) respectively.
The majority of these attacks have been observed to be originating from the cyber space of a number of countries including the US, Europe, Brazil, Turkey, China, Pakistan, Bangladesh, Algeria and the UAE.