How To Check Which Groups You Belong To

In this post, you will get to know about a simple command that lets you know what groups the particular user belongs to. Users and groups are the one of the several concepts employed in the Linux systems for access control.

From the man page, the groups command does is:
Print group memberships for each USERNAME or, if no USERNAME is specified, for the current process (which may differ if the groups database has changed).

So if you are interested in finding what group a particular user is in, run the command as below. Replace samar with your USERNAME and you are good to go:

samar@Techgaun:~$ groups samar

samar : samar adm cdrom sudo vboxusers ....

I hope this proves useful :)


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NCell PRBT Settings Information

This post provides the information regarding how to use the PRBT system provided by NCell.

Original Link: PRBT Information @ Ncell

Q1.What is PRBT?

PRBT service enables the ones who call you to listen to a popular melody or sound instead of the regular tone. The sound or melody is heard by the caller till the call is answered. Your friends and partners, regardless of operator, location and phone model while calling you can hear melodies, sounds and personal greetings chosen by you instead of usual phone tone.

Q2. How to activate PRBT service?

PRBT can be activated by one of the following ways:

I. SMS: On your Message box type A and send it to 900227

II. IVR: Dial 9208 and follow the instruction.

III. USSD: Dial *100*2# and follow the USSD guide instruction.

Q3. How to set a PRBT?

Any PRBT of your choice can be set via SMS, IVR or Web once the user has activated the PRBT service. Stated below are the ways a subscriber can set a PRBT.

I. SMS: Type BUY PRBTcode sends it to 9209.

II. Web :

i. Log on to prbt.ncell.com.np

ii. Click on Order for your choice of PRBT song

III. IVR: Dial 9208 to choose the tone of your choice.

Q4. What are the features with new PRBT system?

The PRBT system allows a subscriber to perform the following:

I. SMS

a. Download multiple PRBTs at once

Example:

DownPRBTcodePRBTcodePRBTcode

b. Gift PRBT to friend

Example: Gift Mobile number

II. Web

To activate any of the features below, the user will have to login with mobile number and password on prbt.ncell.com.np

a. Assign different PRBT to different callers.

i. Click on MY PRBT > PRBT Settings > Advanced Setting

b. Create Group and allocate a PRBT for a group.

i. Click on MY PRBT > Group Management

c. Play different PRBT in different time slots.

i. Click On MY PRBT > PRBT setting > Add

d. Copy a PRBT from a friend.

i. Click on MY PRBT > Copy PRBT

Q5. How much does a PRBT cost and what is the validity?

Each PRBT will attract Rs. 10 excluding the taxes.

Q6. Is there monthly subscription price?

Yes. There will be Rs 10 monthly subscription price without applicable taxes. The subscription will be renewed automatically unless the subscriber chooses to discontinue the service.

Q7. How deactivate PRBT?

You can deactivate by any of the following ways:

I. SMS : In your message box type R and send it to 900227

II. IVR : Dial 900 follow instruction

III. USSD : Dial *100*2# and follow the instruction

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Subterfuge - An Automated MITM Attack Framework

Subterfuge is a very useful tool for hackers and security experts for automating the man-in-the-middle attacks. It provides a complete framework for automating different kinds of MITM attacks.

Subterfuge largely transforms the complexity of performing the man-in-the-middle attacks with the tools such as ettercap and makes it far more easier to launch various form of MITMs. Hence, even a general computer user can perform MITM using this tool. Subterfuge provides a very clear interface accessible over HTTP through browser through which we can view the intercepted authentication data. The tool also supports several other form of MITM attacks such as session injection, http code injection, fake AP, and DNS spoofing.

Currently, the 4.3 beta version of this tool is available as the latest release. You can download the tool and read about the tool at code.google.com/p/subterfuge.

Installation is straightforward. Download the tar file from the above link and then run the following commands in terminal:

samar@samar-Techgaun:~$ tar -xvf SubterfugePublicBeta4.3.tar.gz samar@samar-Techgaun:~$ python install.py -i

After a while, the installation will complete. Now you can run the subterfuge framework by typing subterfuge in your terminal. Enjoy hacking :)
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Simple Sorting Algorithm Using DMA

This post provides the source code for simple and naive integer sorting algorithm by exploiting the dynamic memory allocation feature of C programming.

#include <stdio.h>
#include <stdlib.h>

int main()
{
 int *arr, i, j, n;
 
 printf("Enter the number of items: ");
 scanf("%d", &n);
 
 arr = malloc(n * sizeof(int));
 
 for (i = 0; i < n; i++)
 {
  printf("Enter the %dth item: ", i + 1);
  scanf("%d", &arr[i]);
 }
 
 for (i = 0; i < n - 1; i++)
 {
  for (j = 0; j < n - 1; j++)
  {
   int temp;
   
   if (arr[j] > arr[j + 1])
   {
    temp = arr[j];
    arr[j] = arr[j + 1];
    arr[j + 1] = temp; 
   }
   
  }
 }
 
 printf("The sorted array is:\n");
 
 for (i = 0; i < n; i++)
 {
  printf("%d\n", arr[i]);
 }
 return 0;
}

samar@samar-Techgaun:~$ gcc -Wall -o sort sort.c 
samar@samar-Techgaun:~$ ./sort 
Enter the number of items: 5
Enter the 1th item: 2
Enter the 2th item: 4
Enter the 3th item: 1
Enter the 4th item: 92
Enter the 5th item: 45
The sorted array is:
1
2
4
45
92

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Matrix Multiplication Using DMA [C Source Code]

This post provides a source code for matrix multiplication by dynamically allocating memory for matrices to be multiplied and multiplication of those matrices.

#include <stdio.h>
#include <stdlib.h>

int main()
{
 int **A, **B, **C, m, n, p, q, i, j, k;
 printf("Enter the size of matrix A: ");
 scanf("%d %d", &m, &n);
 
 printf("Enter the size of matrix B: ");
 scanf("%d %d", &p, &q);
 
 if (n == p)
 {
  A = malloc(m * sizeof(int));
  B = malloc(p * sizeof(int));
  C = malloc(m * sizeof(int));
  
  for (i = 0; i < m; i++)
  {
   A[i] = malloc(n * sizeof(int));
   C[i] = malloc(q * sizeof(int));
  }
  
  for (i = 0; i < p; i++)
  {
   B[i] = malloc(q * sizeof(int));
  }
   
  printf("Enter the matrix A:\n\n");
  for (i = 0; i < m; i++)
  {
   for (j = 0; j < n; j++)
   {
    scanf("%d", &A[i][j]);
   }
  }
  
  printf("Enter the matrix B:\n\n");
  for (i = 0; i < p; i++)
  {
   for (j = 0; j < q; j++)
   {
    scanf("%d", &B[i][j]);
   }
  }
  
  for (i = 0; i < m; i++)
  {
   for (j = 0; j < q; j++)
   {
    C[i][j] = 0;
    for (k = 0; k < n; k++)
    {
     C[i][j] = C[i][j] + (A[i][k] * B[k][j]);
    }
   }
  }
  
  printf("Multiplication of given matrices is: \n\n");
  
  for (i = 0; i < m; i++)
  {
   for (j = 0; j < q; j++)
   {
    printf("%d ", C[i][j]);
   }
   printf("\n");
  }
 
  for (i = 0; i < m; i++)
  {
   free(A[i]);
   free(C[i]);
  }
  for (i = 0; i < p; i++)
  {
   free(B[i]);
  }
  free(A);
  free(B);
  free(C);
 }
 else
 {
  printf("Matrix multiplication is not possible for given size\n\n");
 }
 return 0;
}

samar@samar-Techgaun:~$ gcc -Wall -o matrix_mul matrix_mul.c
samar@samar-Techgaun:~$ ./matrix_mul 
Enter the size of matrix A: 3 2
Enter the size of matrix B: 2 3
Enter the matrix A:

1 2
3 4
5 6
Enter the matrix B:

1 2 3
4 5 6
Multiplication of given matrices is: 

9 12 15 
19 26 33 
29 40 51 

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Addition Of Two Matrices Using DMA [C Source Code]

Here is the source code in C that makes use of DMA function malloc() to dynamically allocate the memory for matrices and find their sum.

#include <stdio.h>
#include <stdlib.h>

int main()
{
 int **A, **B, **C, m, n, p, q, i, j;
 printf("Enter the size of matrix A: ");
 scanf("%d %d", &m, &n);
 
 printf("Enter the size of matrix B: ");
 scanf("%d %d", &p, &q);
 
 if (m == p && n == q)
 {
  A = malloc(m * sizeof(int));
  B = malloc(m * sizeof(int));
  C = malloc(m * sizeof(int));
  
  for (i = 0; i < m; i++)
  {
   A[i] = malloc(n * sizeof(int));
   B[i] = malloc(n * sizeof(int));
   C[i] = malloc(n * sizeof(int));
  }
   
  printf("Enter the matrix A:\n\n");
  for (i = 0; i < m; i++)
  {
   for (j = 0; j < n; j++)
   {
    scanf("%d", &A[i][j]);
   }
  }
  
  printf("Enter the matrix B:\n\n");
  for (i = 0; i < m; i++)
  {
   for (j = 0; j < n; j++)
   {
    scanf("%d", &B[i][j]);
   }
  }
  
  for (i = 0; i < m; i++)
  {
   for (j = 0; j < n; j++)
   {
    C[i][j] = A[i][j] + B[i][j];
   }
  }
  
  printf("The addition of two matrices is: \n\n");
  
  for (i = 0; i < n; i++)
  {
   for (j = 0; j < m; j++)
   {
    printf("%d ", C[i][j]);
   }
   printf("\n");
  }
 
  for (i = 0; i < m; i++)
  {
   free(A[i]);
   free(B[i]);
   free(C[i]);
  }
  free(A);
  free(B);
  free(C);
 }
 else
 {
  printf("Matrix addition is not possible for given size\n\n");
 }

 return 0;
}

Below is a sample run along with the compilation step.

samar@samar-Techgaun:~$ gcc -Wall -o matrix_addn matrix_addn.c
samar@samar-Techgaun:~$ ./matrix_addn 
Enter the size of matrix A: 2 2
Enter the size of matrix B: 2 2
Enter the matrix A:

1 2
3 4
Enter the matrix B:

4 3
2 1
The addition of two matrices is: 

5 5 
5 5 

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Transpose Of Matrix Using DMA [C Source Code]

This snippet utilizes the dynamic memory allocation function, malloc() and finds the transpose of the user provided matrix.

Below is the source code:

#include <stdio.h>
#include <stdlib.h>

int main()
{
 int **matrix, **transpose, m, n, i, j;
 printf("Enter the size of matrix: ");
 scanf("%d %d", &m, &n);
  
 matrix = malloc(m * sizeof(int));
 transpose = malloc(n * sizeof(int));
 
 for (i = 0; i < m; i++)
 {
  matrix[i] = malloc(n * sizeof(int));
 }
 
 for (i = 0; i < n; i++)
 {
  transpose[i] = malloc(m * sizeof(int));
 }
  
 printf("Enter the matrix:nn");
 for (i = 0; i < m; i++)
 {
  for (j = 0; j < n; j++)
  {
   scanf("%d", &matrix[i][j]);
  }
 }
 
 for (i = 0; i < m; i++)
 {
  for (j = 0; j < n; j++)
  {
   transpose[j][i] = matrix[i][j];
  }
 }
 
 printf("The transpose of given matrix is: nn");
 
 for (i = 0; i < n; i++)
 {
  for (j = 0; j < m; j++)
  {
   printf("%d ", transpose[i][j]);
  }
  printf("n");
 }

 for (i = 0; i < m; i++)
 {
  free(matrix[i]);
 }
for (i = 0; i < n; i++)
 {
  free(transpose[i]);
 }
 free(matrix);
 free(transpose);
 return 0;
}

Below is the sample run:

samar@Techgaun:~$ gcc -Wall -o transpose transpose.c 
samar@Techgaun:~$ ./transpose 
Enter the size of matrix: 2 3
Enter the matrix:

1 2 3
4 5 6
The transpose of given matrix is: 

1 4 
2 5 
3 6

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Java 0-day In The Wild - Disable Java Plugin NOW

Security researchers have discovered yet another critical Java 0-day exploit being used by majority of the browser exploit packs such as Blackhole and Cool. Users are urged to DISABLE the Java plugin RIGHT NOW.

French researcher Kaffeine discovered that the java 0-day has been spotted to be making big hits daily, in a blog post. This particular exploit has proven to be very serious threat for the users. The folks at AlienVault Lab have also reproduced the exploit and it seems to work over all the java versions across all platforms which is a very serious threat.

As for now, the users are highly urged to disable their JAVA plugins right now so that they do not get hit by these 0-days.

So what are you waiting for?

Important links:

How To Disable Java Plugin

Kaffeine's blog post

Alien Vault Labs Post


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