We have discussed a covert attack, and letting the Greater Manchurians guess who did the work.

It is a covert attack Stand armed with a rapier.

This would prevent terrorist groups, and any states willing to help them, from being able to pull off a covert attack without assurance of retaliation.

Better surveillance would allow medical personnel to determine whether the problem is a seasonal outbreak of influenza or a covert biological attack.

I can't help it if you take every glance and look from our family and friends and my colleagues as some covert attack.

Van discovers the problem and through a covert military-like attack on the source, puts an end to it.

"You know I hate these covert attacks," said he.

We sent him into forbidden space to carry out a covert attack on Thanatos Minor.

This is one of many attacks, both overt and covert, in the field known as Cryptovirology.

He was co-author of a book about the potential horrors of a covert attack.