DDoS Attack - Working and Tools

DDoS Attack

What is DDoS Attack?

• Distributed denial of service (DDoS) attacks is a subclass of denial of service (DoS) attacks. A DDoS attack involves multiple connected online devices, collectively known as a Botnet, which is used to overwhelm a target website with fake traffic.

• A distributed denial-of-service (DDoS) attack is a malicious attempt to disrupt normal traffic of a targeted server, service or network by overwhelming the target or its surrounding infrastructure with a flood of Internet traffic.

• From a high level, a DDoS attack is like a traffic jam clogging up with the highway, preventing regular traffic from arriving at its desired destination.

Difference Between DoS and DDoS Attack?

In a DoS attack, a perpetrator uses a single Internet connection to either exploit a software vulnerability or flood a target with fake requests—usually in an attempt to exhaust server resources (e.g., RAM and CPU).

On the other hand, distributed denial of service (DDoS) attacks is launched from multiple connected devices that are distributed across the Internet. These multi-person, multi-device barrages are generally harder to deflect, mostly due to the sheer volume of devices involved. Unlike single-source DoS attacks.

DDoS attacks also differ in the manner of their execution. Broadly speaking, DoS attacks are launched using homebrewed scripts or DoS tools (e.g., Low Orbit Ion Canon), while DDoS attacks are launched from botnets — large clusters of connected devices (e.g., cell phones, PCs or routers) infected with malware that allows remote control by an attacker.

How does a DDoS attack work?

A DDoS attack requires an attacker to gain control of a network of online machines in order to carry out an attack. Computers and other machines (such as IoT devices) are infected with malware, turning each one into a bot (or zombie). The attacker then has remote control over the group of bots, which is called a botnet.

Once a botnet has been established, the attacker is able to direct the machines by sending updated instructions to each bot via a method of remote control. When the IP address of a victim is targeted by the botnet, each bot will respond by sending requests to the target, potentially causing the targeted server or network to overflow capacity, resulting in a denial-of-service to normal traffic. Because each bot is a legitimate Internet device, separating the attack traffic from normal traffic can be difficult.

What are common types of DDoS attacks?

Different DDoS attack vectors target varying components of a network connection. In order to understand how different DDoS attacks work, it is necessary to know how a network connection is made. A network connection on the Internet is composed of many different components or “layers”. Like building a house from the ground up, each step in the model has a different purpose. The OSI model, shown below, is a conceptual framework used to describe network connectivity in 7 distinct layers.

There are 3 Types of Attacks  -

1. Application Layer attack

2. Protocol Attack

3. Volumetric Attack

Tools Used in DoS/DDoS Attacks -

1. Slowloris

2. LOIC ( Low Orbit Ion Cannon )

3. GoldenEye

4. HOIC ( High Orbit Ion Cannon )

5. XOIC

6. RUDY ( R U Dead Yet ? )

7. TOR's Hammer

8. THC-SSL-DoS

9. Pyloris

10. HULK ( Http Unbreakable Load King )

Andriod Tools -

1. AnDOSid

2. LIOC

Social Engineering - Tactics and Preventions

SOCIAL ENGINEERING

What is Social Engineering?

• Social engineering is the term used for a broad range of malicious activities accomplished through human interactions.

• It uses psychological manipulation to trick users into making security mistakes or giving away sensitive information.

• Social engineering is the art of manipulating users of a computing system into revealing confidential information that can be used to gain unauthorized access to a computer system. 

• The term can also include activities such as exploiting human kindness, greed, and curiosity to gain access to restricted access buildings or getting the users into installing backdoor software.

Note - What makes social engineering especially dangerous is that it relies on human error, rather than vulnerabilities in software and operating systems.

What are some examples of what social engineers say or do?Criminals will often take weeks and months getting to know a place before even coming in the door or making a phone call. Their preparation might include finding a company phone list or org chart and researching employees on social networking sites like LinkedIn or Facebook. 

There are three ways to do it in an organization are -

1. On Phone Call 

2. In Office

3. Online

SOCIAL ENGINEERING ATTACK TECHNIQUESSocial engineering attacks come in many different forms and can be performed anywhere where human interaction is involved. The following are the five most common forms of digital social engineering assaults.

1. Baiting 

Baiting attacks use a false promise to pique a victim’s greed or curiosity. They lure users into a trap that steals their personal information or inflicts their systems with malware.

2. Scareware

Scareware involves victims being bombarded with false alarms and fictitious threats. Users are deceived to think their system is infected with malware, prompting them to install software that has no real benefit (other than for the perpetrator) or is malware itself. Scareware is also referred to as deception software, rogue scanner software, and fraudwares.

3. Pretexting

Here an attacker obtains information through a series of cleverly crafted lies. The scam is often initiated by a perpetrator pretending to need sensitive information from a victim so as to perform a critical task.

The attacker usually starts by establishing trust with their victim by impersonating co-workers, police, bank and tax officials, or other persons who have right-to-know authority. The pretexter asks questions that are ostensibly required to confirm the victim’s identity, through which they gather important personal data.

4. Phishing

As one of the most popular social engineering attack types, phishing scams are email and text message campaigns aimed at creating a sense of urgency, curiosity or fear in victims. It then prods them into revealing sensitive information, clicking on links to malicious websites, or opening attachments that contain malware.

5. Spear Phishing

This is a more targeted version of the phishing scam whereby an attacker chooses specific individuals or enterprises. They then tailor their messages based on characteristics, job positions, and contacts belonging to their victims to make their attack less conspicuous. Spear Phishing requires much more effort on behalf of the perpetrator and may take weeks and months to pull off. They’re much harder to detect and have better success rates if done skillfully.

NOTE - To perform social engineering attacks for educational purpose you can use Social Engineering Toolkit (SET) in Kali Linux.

How to Defend Yourself from Social Engineers?

Social engineers manipulate human feelings, such as curiosity or fear, to carry out schemes and draw victims into their traps. Therefore, be wary whenever you feel alarmed by an email, attracted to an offer displayed on a website, or when you come across stray digital media lying about. Being alert can help you protect yourself against most social engineering attacks taking place in the digital realm.

• Don’t open emails and attachments from suspicious sources – If you don’t know the sender in question, you don’t need to answer an email. Even if you do know them and are suspicious about their message, cross-check and confirm the news from other sources, such as via telephone or directly from a service provider’s site. Remember that email addresses are spoofed all of the time; even an email purportedly coming from a trusted source may have actually been initiated by an attacker.
• Use multifactor authentication – One of the most valuable pieces of information attackers seek are user credentials. Using multifactor authentication helps ensure your account’s protection in the event of system compromise. Imperva Incapsula Login Protect is an easy-to-deploy 2FA solution that can increase account security for your applications.
• Be wary of tempting offers – If an offer sounds too enticing, think twice before accepting it as fact. Googling the topic can help you quickly determine whether you’re dealing with a legitimate offer or a trap.
• Keep your antivirus/antimalware software updated – Make sure automatic updates are engaged, or make it a habit to download the latest signatures first thing each day. Periodically check to make sure that the updates have been applied, and scan your system for possible infections.

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.

Footprinting - Tools and Methods

FOOTPRINTING

Footprinting is a part of reconnaissance process which is used for gathering possible information about a target computer system or network. Footprinting could be both passive and active. 

Footprinting is a first and the important step because after this a penetration tester knows how the hacker sees this network.

To measure the security of a computer system, it is good to know more and more as you can because after this you will able to determine the path that a hacker will use to exploit this network. 

Here is Scenario of the Footprinting - 

 The EC-Council divides footprinting and scanning into seven basic steps. These include

1. Information gathering
2. Determining the network range
3. Identifying active machines
4. Finding open ports and access points
5. OS fingerprinting
6. Fingerprinting services
7. Mapping the network

Information gathering means to find these:

Internet: Domain name, network blocks, IP addresses open to Net, TCP and UDP services running, ACLs, IDSes

Intranet: Protocols (IP,NETBIOS), internal domain names, etc

Remote Access: Phone numbers, remote control, telnet, authentication Extranet: Connection origination, destination, type, access control

Website on an organisation is a first place from where penetration testing start, you can get the sensitive information about the network by using websites, you can get Phone Numbers, Contact Names, E-mail Addresses, and Personal Details. Beside the official website of the company an attacker might be use some social networking website like facebook to gather the appropriate information. Some other resources and a website that an attacker may use to get the maximum information about the organisation and it employees are:

zabasearch.com—Contains names, addresses, phone numbers, date of birth, and other information about individuals.

anywho.com—Phone book offering forward and reverse lookups.

maps.yahoo.com—Yahoo! map site. 

You can use the facility of a search engine to perform footprinting,search engine like google, yahoo or altavista provide the plate form to gather the information. Advance google dorks may be use to get the information like:

Filetype: This operator directs Google to search only within the test of a particular type of file.
        Example: filetype:xls

Inurl: This operator directs Google to search only within the specified URL of a document.
     Example: inurl:search-text

Link: The link operator directs Google to search within hyperlinks for a specific term.
    Example link:www.domain.com

Intitle: The intitle operator directs Google to search for a term within the title of a document.
       Example intitle: “Index of...etc”

Footprinting helps to -
1. Know Security Posture – The data gathered will help us to get an overview of the security posture of the company such as details about the presence of a firewall, security configurations of applications etc.
2. Reduce Attack Area – Can identify a specific range of systems and concentrate on particular targets only. This will greatly reduce the number of systems we are focussing on.
3. Identify vulnerabilities – we can build an information database containing the vulnerabilities, threats, loopholes available in the system of the target organization.
4. Draw Network map – helps to draw a network map of the networks in the target organization covering topology, trusted routers, presence of server and other information.