Virus Name: Kthulhu
V Status: Rare
Discovered: December, 1992
Symptoms: .COM file growth; message displayed; system hangs;
write protect errors on diskettes
Eff Length: 512 Bytes
Type Code: PNCK - Parasitic Non-Resident .COM Infector
Detection Method: ViruScan, AVTK, F-Prot, Sweep, IBMAV,
NAV, NAVDX, VAlert, PCScan, ChAV,
NShld, Sweep/N, NProt, AVTK/N, LProt, NAV/N, IBMAV/N,
Removal Instructions: Delete infected programs
The Kthulhu virus was submitted in December, 1992. It is originally
from Poland. Kthulhu is a non-resident, direct action infector of
.COM programs, including COMMAND.COM.
When a program infected with the Kthulhu virus is executed, the
Kthulhu virus will infect all of the .COM programs located in the
current directory. Infected programs will have a file length
increase of 512 bytes with the virus being located at the beginning
of the file. The program's date and time in the DOS disk directory
listing will not be altered. The following text strings can be
found within the viral code in all Kthulhu infected programs:
"KTHULHU Today is my birthday."
"IT $is coming."
The Kthulhu virus activates when an infected program is executed
during the month of May of any year, displaying a message. A
system hang also occurs. The text of the message depends on what
the day of the month is set to in the system time. From the 1st
of May thru May 19th, the message displayed is:
"IT is coming."
On May 20th, it displays the message:
"Today is my birthday."
From May 21st thru May 31st, it displays the message:
"IT has gone.
An additional symptom of a Kthulhu infection is that attempts to
execute programs on write protected diskettes will result in a
write protect error.