letterbomb
1. n. A piece of email containing
live data intended to do
nefarious things to the recipient's machine or terminal. It used
to be possible, for example, to send letterbombs that would lock
up some specific kinds of terminals when they are viewed, so
thoroughly that the user must cycle power (see cycle, sense 3) to unwedge them. Under Unix, a
letterbomb can also try to get part of its contents interpreted
as a shell command to the mailer. The results of this could range
from silly to tragic; fortunately it has been some years since
any of the standard Unix/Internet mail software was vulnerable to
such an attack (though, as the Melissa virus attack demonstrated
in early 1999, Microsoft systems can have serious problems). See
also Trojan horse; compare
nastygram. 2. Loosely, a mailbomb.