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- ________________________________________________________________________
- THE COMPUTER INCIDENT ADVISORY CAPABILITY
-
- CIAC
-
- INFORMATION BULLETIN
- ________________________________________________________________________
-
- The Disk Killer (Orge) Virus on MS DOS Computers
-
-
- June 28, 1990, 1000 PST Number A-27
-
- ________________________________________________________________________
- Name: Disk Killer virus (also known as the Ogre virus)
- Types: Only one known variant
- Platform: MS DOS computers
- Damage: Overwrites mounted disks
- Symptoms: Writes "COMPUTER OGRE 04/01/89" on screen and overwrites disk
- Detection/Eradication: VIRALERT, VIRHUNT, RESSCAN, CodeSafe, CleanUp,
- F-Prot, IBM Scan, Pro-Scan, and others (contact CIAC for information
- about these products)
- Critical Disk Killer Facts
- ________________________________________________________________________
-
- The Disk Killer virus is a destructive virus affecting MS DOS
- computers. This virus infects the boot sector, then hides itself by
- marking unused blocks on floppy or hard disks as bad. After remaining
- dormant for approximately 48 hours of operation (not calendar) time
- after the initial infection, Disk Killer executes upon the first boot
- or reboot after this period. Upon execution, this virus displays the
- following message:
-
- Disk Killer -- Version 1.00 by COMPUTER OGRE 04/01/89
-
- Warning!!
-
- Don't turn off the power or remove the diskette while Disk Killer
- is Processing!
-
- Next, the word "PROCESSING" will be displayed, followed by this message:
-
- Now you can turn off the power. I wish you Luck!
-
- Disk Killer overwrites the boot sector, then the file allocation table
- (FAT), then the directory randomly with blocks of a single character.
-
- The proper procedure depends upon when you detect Disk Killer:
-
- 1. If your machine is infected before it executes and you detect this
- virus through a scan package (such as CodeSafe, RESSCAN, VIRHUNT, or
- IBM Scan)---TURN YOUR MACHINE OFF. Then use a write-protected bootable
- floppy disk to boot your system; otherwise, you will have disk Killer
- in memory, causing re-infection. Remove Disk Killer by installing and
- executing a PC virus eradication package such as VIRHUNT.
-
- 2. If the message shown above appears on your computer's screen, Disk
- Killer has already executed---LEAVE YOUR MACHINE ON AND ALLOW THIS
- VIRUS TO EXECUTE WITHOUT INTERRUPTION (i.e., until "Now you can turn
- off the power..." is displayed). It is true that Disk Killer will
- overwrite your disk, but don't worry---you can restore all data and
- files from your disk (floppy or hard disk) using a recovery package
- such as UNKILL. Reboot from a write-protected master floppy, and
- remove the virus using virus eradication software.
-
- Regardless of which particular procedure (1 or 2) you use, be sure to
- scan any disks (in particular, bootable floppies) before resuming
- normal activity with your computer.
-
- Note: Because this virus modifies every byte in every sector on your
- disk, Norton Utilities not a feasible means of recovering from the Disk
- Killer virus. Note also that a considerable amount of incorrect
- information about responding to Disk Killer has already been
- distributed. If you follow this incorrect information, which advises
- you to turn your machine off as soon as Disk Killer begins to execute,
- it is extremely likely that you will not be able to fully recover from
- this virus.
-
- Additional Note: The CIAC team first became aware of this virus early
- last Fall. At that time, however, we chose to briefly describe this
- virus in the CIAC Bulletin Board (FELIX) and CIAC Bulletin A-15, rather
- than to issue a separate bulletin; infections at that time appeared to
- be limited to MS DOS computers equipped with hard disks made by a
- particular manufacturer in Taiwan.
-
- For additional information or assistance, please contact CIAC:
-
- David S. Brown
- (415) 423-9878 or (FTS) 543-9878
- FAX: (415) 423-0913, (FTS) 543-0913 or (415) 422-4294
-
- Send e-mail to:
-
- ciac@tiger.llnl.gov
-
- Neither the United States Government nor the University of California
- nor any of their employees, makes any warranty, expressed or implied,
- or assumes any legal liability or responsibility for the accuracy,
- completeness, or usefulness of any information, product, or process
- disclosed, or represents that its use would not infringe privately
- owned rights. Reference herein to any specific commercial products,
- process, or service by trade name, trademark manufacturer, or
- otherwise, does not necessarily constitute or imply its endorsement,
- recommendation, or favoring by the United States Government or the
- University of California. The views and opinions of authors expressed
- herein do not necessarily state or reflect those of the United States
- Government nor the University of California, and shall not be used for
- advertising or product endorsement purposes.