"letter bomb." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/letter-bomb>.
letter bomb. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/letter-bomb
(plural letter bombs)
An e-mail or word processing document that contains active code intended to cause damage to the recipient's computer such as erasing the hard disk. See macro virus and mail bomb.