NEW DELHI: After the Armed Forces were attacked by cyber crooks on Friday late night , the tri-services cyber wings issued emergency warning to all the defence personnel not to access mail titled -- 'Notice' -- with attachments, sources said on Saturday.

"A Phishing email with subject as 'Notice' containing a hyperlink named HNQ Notice File.xls download is being sent out to the defence personnel specifically from the email id prvinayak.598k@gov.in," the emergency alert stated.

The alert also pointed that any email with the above subject, originator and link be treated with caution. "Do not access the email from the inbox if received. Report or delete it immediately," the alert stated.

A senior Indian Army officer said cyber attacks on India's critical infrastructure are originating either from Pakistan or China. "Our cyber units are on high alert as such attacks have increased in recent times," the officer said.