Among other definitions for "Snark" at the Free Online Dictionary of Computing, Dictionary.com, and other Web dictionaries you'll find:
[Lewis Carroll, via the Michigan Terminal System]This definition appears hundreds of times on the Web. Try a Google search and see for yourself!
1. A system failure. When a user's process bombed, the operator would get the message "Help, Help, Snark in MTS!"
2. More generally, any kind of unexplained or threatening event on a computer (especially if it might be a boojum). Often used to refer to an event or a log file entry that might indicate an attempted security violation. See snivitz.
3. UUCP name of snark.thyrsus.com, home site of the Hacker Jargon File versions 2.*.*.