The hackers had a message on the home page that said - the 'Pakistan Cyber Army' is warning the Indian Cyber Army not to attack their websites. The CBI website, that is supposed to be one of the most secure websites, has still not been restored.
"This is not a mere hacking. Its an act of cyber terrorism," says cyber lawyer Pawan Duggal.
The self-proclaimed Pakistan Cyber Army claims it has also defaced another 270 websites. Cyber experts say defacement of websites happens quite regularly, but given that a high profile government website has been hacked, cyber security procedures need to be looked into.
Rajat Khare, a cyber security expert told NDTV, " The site was never audited. There is a government policy, that if you host a government site it needs to be audited. But the site was running for over a year."
Kapil Sibal, the Minister for Science and Tecnology has promised to look into the matter.
Experts hope it was just a defacement and no data has been stolen. The server that hosts the website is different from the one that manages the e-mail through which confidential correspondence takes place. The CBI has registered a case against unknown persons with its cyber-crime cell and the National Informatics Centre that maintains most government websites is probing the case.