[1] : Jargon File (4.3.1, 29 Jun 2001)

sig virus n. a parasitic meme embedded in a sig block. there was a
   meme plague or fad for these on usenet in late 1991. most were
   equivalents of "i am a .sig virus. please reproduce me in your .sig
   block.". of course, the .sig virus's memetic hook is the giggle value of
   going along with the gag; this, however, was a self-limiting phenomenon
   as more and more people picked up on the idea. there were creative
   variants on it; some people stuck `sig virus antibody' texts in their
   sigs, and there was at least one instance of a sig virus eater.


see also:
meme sig block meme plague 

[2] : The Free On-line Dictionary of Computing (27 SEP 03)

sig virus
     
        a parasitic meme embedded in a sig block.  there was a
        meme plague or fad for these on usenet in late 1991.  most
        were equivalents of "i am a .sig virus.  please reproduce me
        in your .sig block.".  of course, the .sig virus's memetic
        hook is the giggle value of going along with the gag; this,
        however, was a self-limiting phenomenon as more and more
        people picked up on the idea.  there were creative variants on
        it; some people stuck "sig virus antibody" texts in their
        sigs, and there was at least one instance of a sig virus
        eater.
     
        jargon file
     
     
see also:
meme sig block meme plague usenet jargon file 

Coxsackie Virus >> C Words
Coxsackie Virus, definition of term: Coxsackie Virus
coxsackie+virus_pag1.html

Computer Virus >> C Words
Computer Virus, definition of term: Computer Virus
computer+virus_pag1.html