"Lehigh" Virus (30-June-1990)
Entry...............: "Lehigh" Virus
Alias(es)...........: ---
Virus strain........: ---
Virus detected when.: November 1987
              where.: Lehigh University (Bethlehem/USA)
Classification......: System virus (COMMAND.COM), RAM-resident
Length of virus.....: 555 bytes
--------------------- Preconditions ----------------------------------
Operating system(s).: MS-DOS
Version/release.....: 2.0 and higher
Computer model(s)...: All MS-DOS machines
--------------------- Attributes -------------------------------------
Easy identification.: Last two bytes of COMMAND.COM = A9h 65h;
                           text found: ":\command.com".
Type of infection...: COMMAND.COM only (stack space at end of file
                           overwritten); RAM resident (no check if
                           RAM infected before).
Infection trigger...: Uninfected COMMAND.COM in the root directory of
                           used or current drive (checked by INT 21h)
Storage media affected: Any COMMAND.COM on hard disk or diskette.
Interrupts hooked...: INT 21h; INT 44h (Set as old INT 21h).
Damage..............: If A: or B: selected (if it is not the current
                           drive), then sector 1 to 32 are overwritten
                           with garbage read from BIOS and print-text
                           (also from BIOS).
Damage trigger......: Infection counter = 4
Particularities.....: Not hardware-dependent: INT 21h, 26h used only
Similarities........: ---
--------------------- Agents -----------------------------------------
Countermeasures.....: ---
Countermeasures successful: Several antiviruses (McAfee, Solomon,
                            Skulason et.al.) successfully detect and
                            eradicate this virus.
Standard means......: ---
--------------------- Acknowledgement --------------------------------
Location............: Virus Test Center, University Hamburg, FRG
Classification by...: Daniel Loeffler (disassembly by Joe Hirst)
Documentation by....: Daniel Loeffler
Date................: June 30, 1990
Information Source..: ---

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