A malicious mail containing a dangerous computer virus from the email ID of the Indian Ambassador in Uzbekistan to some senior officials of the Home Ministry has sent alarm bells ringing in the security establishment here.

It is feared that the mail box of the diplomat may have been compromised by hackers.

The 'trojan' virus concealed inside a sham list of indigenous Indian terrorists has even escaped the Trend Micro Anti-virus software deployed by the government's IT arm National Informatics Centre (NIC) in the official computers.

"The Intelligence Bureau has intimated that a number of senior officers in Ministry of Home Affairs have received a malicious mail from the email ID containing a 'Trojan' concealed inside a sham list of indigenous Indian terrorists," an official circular said.

After detecting the virus, the IB swung into action immediately for damage limitation and advised a number of procedures to be followed by all officials who use computers in the North Block premise.

Investigators believe that the hackers, based in a foreign country, cracked the official email ID of the Indian Ambassador to Uzbekistan and sent the mail with an intention to infiltrate in the Home Ministry computer networks.

The IB has also advised that all computers in MHA are regularly updated with latest anti-virus operating system and application software (MS Office, Acrobat Reader etc.) Patches and no Internet connected computer should be used to process, store or transmit sensitive official documents.

"There is proper control over the use of Computer Storage Media (CSM). If the same Pen Drive is used in standalone and Internet computers, all precautions should be taken to ensure that Pen Drive is treated with anti-virus software and there is no hidden folder," the IB advisory said.

Earlier also similar attempts have been made to infiltrate into the computers of sensitive Ministries, including Home and External Affairs, allegedly by Chinese hackers.

The government is also taking action to fight back the hackers. National Security Advisor Shiv Shankar Menon had held a high-level security meeting on July 29 which was attended by Director of Intelligence Bureau Rajiv Mathur as well as senior officials of Department of Telecommunication and security agencies.