%%File: VIRS0731.TXT
%%Name/Aliases: Sunday, Sunday-B, Sunday-C
%%Platform: PC/MS-DOS
%%Type: Program., 
%%Disk Location: COM application., EXE application., Program overlay 
files.
%%Features: Memory resident; TSR.
%%Damage: Interferes with a running application., Corrupts a program or 
overlay files.
%%Size: 1636, 1644, 1631, uses INT 21 subfunction FF to check for prior 
infections
%%See Also: Jerusalem
%%Notes: Infects .OVL, .COM and .EXE files.  It is a memory resident 
virus.  It can affect system run-time operations.  It appears to be a 
"Jerusalem" variant, with modifications at the source code level to make 
this a separate and distinct virus (i.e. not a mutation of Jerusalem).  
First discovered in Seattle, WA in November 1989.  Three variants exist.  
FAT damage has been reported, but not confirmed.  Each of the three 
variants adds a different amount of bytes to files, it is not yet known 
which size is for which variant.  One variant only is damaging; it 
activates on Sundays and displays a message.  The other two variants 
have a bug which stops this action, and do not cause FAT damage.  Works 
well on LANs  Activation on Sundays and displays message "Today is 
Sunday!  Who do you work so hard?  All work and no play make you a dull 
boy.  C'mon let's go out and have fun!" then may cause FAT damage   Find 
with standard detection/eradication packages  FPROT 2.00, probably 
earlier versions, most commercial scanners.