Possible virus by US Government to plant child porn on PC

I was told by a computer  illiterate person, whom I shall give the pseudonym "Sally Smith" that she was asked to put child porn on my laptop.  Sally did not know how to do it, and supposedly they had a device to do it, and said "Peter is gay, so he probably looks at child porn anyhow."  I showed Sally a thumbnail drive, and she said "Yes, that's the device which they gave me to my home, but then asked for it back."

I have read about 1-2 cases (one in India), but to have the DEA/ATF do that is really bad.  And I trust Sally since she did not know the details, and it was only later I found out that this method would not have child porn on the drive (which is illegal), but would connect to the web and download child porn.

Is this a known virus, and can Norton Antivirus Security stop it?