1)Ransomware is a type of harmful software (malware) that locks your computer or your files,

making them inaccessible, and demands money (a ransom) to unlock them.

How it works:

1. Infection: Ransomware can get into your computer through unsafe links, email attachments,
or weak spots in your network security.

2. Locking Data: Once inside, it either locks your entire system or encrypts your files (scrambles
them so they can’t be used).

3. Ransom Demand: A message appears demanding payment (usually in cryptocurrency) to

restore access to your computer or files.

Example in simple terms:

Imagine a thief breaks into your house, changes the lock on your door, and says, "Pay me money if
you want the key to get back inside." That’s how ransomware works for computers.

How to stay safe:

 Don’t open unknown email attachments or click suspicious links.

 Keep backups of your important files on an external drive or cloud.

 Use antivirus software and keep it updated.

 Update your system regularly to fix security flaws.

By being cautious, you can reduce the risk of falling victim to ransomware.

2) A proxy server is like a middleman between your computer and the internet. It helps relay your
requests to other websites or services and then sends the responses back to you.

How attackers misuse it:

1. Using a Proxy Server: An attacker connects to the proxy server instead of directly accessing
their target (a website or system).

2. Hiding Their Identity: Since the proxy server is the one communicating with the target, it
hides the attacker’s real identity and location.

3. Launching Anonymous Attacks: The attacker can carry out malicious activities, like hacking
or stealing data, while staying anonymous because the target system only sees the proxy
server, not the attacker.

Example in simple terms:

Imagine a person sends a message to someone through a mutual friend instead of directly. If the
mutual friend doesn’t reveal who the original sender is, the recipient won’t know where the message
really came from. Similarly, a proxy server hides the attacker’s true identity.

Why this is dangerous:

 It makes it harder to trace attackers.

  Attackers can bypass restrictions or filters using the proxy.

How to protect against misuse:

 Monitor traffic on your network for suspicious activities.

 Use secure systems to avoid unauthorized access to proxy servers.

 Block known malicious proxies using firewalls or updated security tools.

3) A proxy server acts as an intermediary between a user's device and the internet. It receives
requests from a client (like a web browser), forwards those requests to the appropriate server, and
then returns the response to the client. Proxy servers are used for various purposes, including
privacy, security, and performance optimization.

How It Works:

1. Client Sends Request: A client device sends a request to access a website or resource.

2. Proxy Server Intercepts: The proxy server intercepts the request.

3. Processes or Forwards Request: The proxy can either process the request (e.g., check for
caching or content filtering rules) or forward it to the target server.

4. Receives Response: The proxy receives the response from the target server.

5. Returns Response to Client: The proxy sends the server's response back to the client.

4) An anonymizer or anonymous proxy is a tool that helps keep your internet activity private and
untraceable. Here’s how it works in simple terms:

 When you browse the internet, your computer sends a request directly to a website, and
the website can see your IP address (your computer’s unique identifier on the internet).
This can reveal your location and identity.

 An anonymizer steps in as a middleman. Instead of your computer contacting the website

directly, the anonymizer sends the request for you. The website only sees the anonymizer’s
information, not yours.

 This way, your personal details, like your IP address, stay hidden, making it hard for anyone
to track your online activity or figure out who you are.

Why People Use It:

1. Privacy: To prevent websites or others from knowing their identity or location.

2. Bypass Restrictions: To access content that might be blocked in their country or region.

3. Security: To avoid being tracked by advertisers, hackers, or even government agencies.

Example:

Imagine you’re writing a letter but don’t want the recipient to know it’s from you. You send the
letter to a trusted friend (the anonymizer), and they forward it to the recipient without including
your details. Similarly, the recipient’s response comes back through your friend, so your identity
remains hidden.

1)Keylogging, or keystroke logging, is a way to secretly record what someone types on a keyboard.
The person using the computer doesn’t know this is happening. A keylogger is a tool used to
capture everything typed, such as passwords or messages.

There are two types of keyloggers:

1. Software Keylogger: A program installed on the computer that tracks what is typed.

2. Hardware Keylogger: A small device connected to the keyboard or inside the computer
that does the same thing.

Keylogging is often used by cybercriminals to steal personal information, but it can also be used for
legitimate purposes like monitoring employee activity or tracking children’s online behavior.

2)Software keyloggers are programs that secretly record everything you type on your computer.
They sit between the keyboard and the operating system, so they can capture every key you press.

These keyloggers are often installed by harmful software like viruses or Trojans without you
knowing. Once installed, they usually have two important files:

1. DLL File (Dynamic Link Library): This file does the actual work of recording the keys you
press.

2. EXE File (Executable): This file starts the keylogger and makes the DLL file start recording.

Together, these files help the keylogger run in the background, quietly capturing keystrokes
without being noticed.

3) A hardware keylogger is a small device that is physically attached to a computer or keyboard. It

captures and saves everything typed on the keyboard.

To use a hardware keylogger, someone needs physical access to the computer or machine to
connect it. These devices store the recorded keystrokes in their memory or a file.

Cybercriminals often use hardware keyloggers on ATMs to secretly capture PINs when people enter
them, making them a serious security threat.

4)Anti keyloggers:
An antikeylogger is a tool designed to find and remove keyloggers from a computer, keeping your
system safe.

Why is it useful?

 Firewalls can’t spot keyloggers: Regular firewalls often miss keyloggers, but an
antikeylogger can detect and stop them.

 No regular updates needed: Unlike antivirus programs that need constant updates,
antikeyloggers work effectively without frequent updates.

Benefits:

 Protects your personal information: It prevents identity theft by stopping keyloggers from
stealing your passwords and sensitive data.

 Secures communication: Ensures safe email, chatting, and instant messaging by protecting
what you type.

5) Spyware is harmful software that secretly watches what you do on your computer without you
knowing.

How it works:

 Hidden activity: Spyware runs quietly in the background, so users don’t know it’s there.

 Purpose: Sometimes, it’s installed on shared or public computers to monitor what others
are doing, like tracking their typing or browsing.

What it does:

 Collects personal data: It gathers information like the websites you visit and your online
habits.

 Slows down your device: Spyware can make your internet slower and cause your computer
to lag.

How to protect yourself:

To stop spyware, you can use anti-spyware software, which finds and removes these programs,
keeping your computer and personal information safe.

6) A computer virus is a harmful program that attaches itself to other legitimate programs and
spreads to other computers without users knowing.

How it works:

 Self-spreading: It copies itself and moves from one computer to another, often through
shared files, emails, or downloads.

 Hidden danger: Users usually don’t know the virus is there until it causes damage.

What it can do:

  Harmful actions: Some viruses can damage files, slow down your computer, or steal data.

 Triggered events: A virus might activate at a specific time, after a certain action, or
randomly.

In simple terms, a virus is like a sneaky bug that hides in your computer, spreads to others, and can
cause serious problems.

TYPES OF VIRUSES:

7)1) Boot sector viruses are harmful programs that infect the part of a storage device (like a hard
drive or floppy disk) responsible for starting the computer. This part is called the boot sector and
contains important information, like the Master Boot Record (MBR), which helps load the
operating system.

How it works:

1. Infection begins: If a virus infects the boot sector of a floppy disk, it can spread to a
computer’s hard drive when the system starts with the infected disk inserted.

2. Spreads further: Once the hard drive is infected, any disk used in that system will also
become infected.

3. Continues to spread: These infected disks can then spread the virus to other computers
when shared.

In simple terms, a boot sector virus is like a chain reaction: it starts from one infected disk, spreads
to the computer, and then to other disks and computers, causing widespread damage.

2) Program viruses:

These viruses activate when you open or run a program file, usually one with extensions
like .bin, .com, or .exe.

How it works:

1. Activation: The virus hides inside a program file and starts working when you open or run
that file.

2. Spreading: Once active, the virus makes copies of itself and spreads to other programs on
your computer.

In simple terms, these viruses are like hidden hitchhikers in program files that spread and cause
damage when the programs are used.

3) Multipartite viruses:

This type of virus is a combination of a boot sector virus and a program virus.

How it works:
 1. Dual infection: It infects both the boot record (the part of your computer that helps it
start) and the program files.

2. Activation: When you run an infected program, the virus becomes active and spreads to
both the boot record and other program files.

In simple terms, it’s a virus that attacks in two ways—damaging the computer’s startup system and
spreading through program files.

4) Stealth viruses

are sneaky types of viruses that hide and make themselves hard to detect.

How it works:

1. Camouflage: The virus hides its presence by changing how it looks. It can hide inside files
or in the computer’s memory so that antivirus software can’t find it.

2. Hides itself: It might change the size of its file or hide in areas that are harder to scan,
making it even more difficult for security tools to detect.

The first stealth virus was called Brain. In simple terms, stealth viruses are like invisible
troublemakers—they hide from you and antivirus programs to stay undetected and cause damage.

5) Polymorphic viruses:

A polymorphic virus acts like a chameleon. Every time it spreads to a new system, it changes its
appearance or code, making it hard to detect. Since it keeps changing, regular antivirus programs
have trouble finding it.

6)Macroviruses:

Many programs, like Microsoft Word and Microsoft Excel, allow users to create macros—small
automated commands to simplify tasks. However, macroviruses use these macros to infect
documents or spreadsheets. When you open or use an infected document, the virus can spread.

In simple terms:

 A polymorphic virus keeps changing its look to hide.

 A macrovirus hides in macros (automated tasks) inside programs like Word and Excel to
spread.

7) Active X and Java Control:

Active X and Java Controls are features used by web browsers to allow certain functions on
websites, like:

 Allowing pop-ups to appear.

  Enabling file downloads.

 Scanning your computer with online antivirus tools.

Benefits:

 They help websites and online tools work properly, like running antivirus scans or enabling
certain website features.

Risks:

 Security threats: Some malware can use Active X to go beyond the browser's protection
and access your computer.

 External access: Because Active X can interact with other parts of your computer, it can be
used by malicious programs to cause harm.

In simple terms, while Active X and Java Controls are useful for certain online tasks, they can also
be risky because they might let harmful software sneak past your browser's security.

8) Trojan Horses

A Trojan Horse is a type of malware that looks like a harmless program but actually contains
harmful code that can cause damage to your computer.

How it works:

 Looks harmless: The Trojan appears to be something safe or useful, like a fun screen saver
or a game.

 Hides danger: Inside, it has hidden harmful functions, like stealing your data or allowing
hackers to access your computer.

How Trojans get into your system:

 They can come from web browsers, emails, or downloaded software from the internet.

 No self-replication: Unlike viruses, Trojans don’t spread by themselves, but they can still
cause a lot of harm.

Example:

 For example, a file named waterfalls.scr might seem like a harmless waterfall screen saver,
but it could actually be a Trojan. When opened, it can secretly install harmful programs or
allow hackers to control your PC without you knowing.

In simple terms, a Trojan is like a hidden threat inside a seemingly safe program that can cause
serious damage to your computer.

9)BACKDOORS:

A backdoor is a way into a computer that bypasses normal security measures, allowing someone
to access the system without permission.
How it works:

1. Used for troubleshooting: Sometimes, programmers create backdoors to help with

maintenance or fixing issues, but they are meant to be used by trusted people.

2. Malicious use: Attackers use backdoors to secretly control a computer. They might find or
install a backdoor to gain unauthorized access.

Why it’s dangerous:

 Hidden from the user: The backdoor runs in the background, so the person using the
computer usually doesn’t know it’s there.

 Full control: A backdoor allows someone to do anything on the computer, like stealing
data, installing more malware, or controlling the system remotely.

In simple terms, a backdoor is like a secret entrance to your computer that lets someone else
control it without you knowing. It's one of the most dangerous types of malware because it gives
the attacker full access to your system.

Examples of Backdoor Trojans:

1)Back Orifice

Back Orifice is a type of malicious software (Trojan) that allows someone to secretly control
another computer from far away, as long as it's running a Windows operating system. It was
originally made for remote administration (managing computers remotely), but it can be misused
by attackers to take over a computer without permission.

2)Bifrost

Bifrost is another malicious program (Trojan) that works similarly to Back Orifice. It can infect older
versions of Windows, like Windows 95 and Windows Vista. It operates using three components:

1. Server: Installed on the victim's computer to give access.

2. Server Builder: Used by the attacker to create the server program.

3. Client Program: Used by the attacker to connect to and control the victim's computer.

3) SAP and Backdoors (Simple Explanation)

SAP is software used by businesses to manage their daily operations, like buying and selling
products, keeping track of inventory, paying employees, and planning finances. Think of it as the
brain of a company’s technology, helping different parts of the business work together smoothly.

A backdoor in SAP is like a hidden entrance that hackers or unauthorized users could use to get
into the system. If someone creates or finds a backdoor in SAP, they might be able to secretly
access important company information, such as employee details, financial records, or stock levels,
and even manipulate these processes. This could seriously harm the business.

So, keeping SAP systems secure is crucial to protect sensitive data and ensure the company runs
without disruptions.
4) Onapsis Bizploit (Simple Explanation)

Onapsis Bizploit is a free tool created by security experts to test how safe ERP systems are (like
SAP). ERP systems are used by businesses to manage important tasks like finances, inventory, and
payroll.

Bizploit helps security professionals find weaknesses in these systems, check if hackers could
exploit them, and test how vulnerable they are to attacks. It’s like a toolbox for testing ERP systems
to make sure they’re secure and protected from potential threats.

10) Steganography (Simple Explanation)

Steganography is a way of secretly hiding a message inside another message, image, or file so that
no one realizes the secret message is there. The idea is not just to keep the content hidden, but to
make sure people don't even suspect there’s a hidden message in the first place.

For example:

 You could hide a secret text message inside a picture file. To anyone else, the picture looks
normal, but the intended person knows where and how to find the hidden message.

It’s like writing a note in invisible ink—only the sender and receiver know it’s there.

11) Steganalysis (Simple Explanation)

Steganalysis is the process of finding hidden messages in files, images, or other data. Its goal is to
figure out if something, like a picture or document, has been secretly altered to include a hidden
message and, if possible, uncover that message.

Think of it as detective work to expose secrets that someone tried to hide using steganography.
There are tools, like StegExpose, StegAlyzer, and StegSpy, that help in detecting these hidden
messages by analyzing the files for anything unusual.

12)1) Bandwidth attacks:

Websites need a certain amount of "internet capacity" to stay online and serve visitors. This
capacity is called bandwidth, like how a water pipe has a limit to how much water it can carry. For
example, a website might have 50 GB of bandwidth to use in a month.

In a bandwidth attack, a bad person (the attacker) tries to use up all this bandwidth quickly so the
website can't serve other people. They do this by opening many pages of the site at the same time
—like 100 pages—and then keep refreshing them over and over. It's like turning on all the taps in
your house at once to waste water.

When all the bandwidth is used up, the website can no longer work for anyone else. It becomes
unavailable or "out of service" until the bandwidth is increased or reset.
2) Logic attacks:

Websites and networks run on programs and systems (like the web server or the TCP/IP stack) that
follow specific rules or "logic" to handle user requests. These rules are like instructions: "If this
happens, do that."

In a logic attack, the attacker finds a mistake or weakness in these rules. Instead of overwhelming
the system with traffic (like in a bandwidth attack), they send specific tricky requests designed to
confuse or break the system.

For example:

 If the web server expects a regular request but the attacker sends a weird or unexpected
one, the server might not know what to do and crash.

 If the TCP/IP stack has a flaw in how it handles data packets, the attacker can send fake
packets to make it behave incorrectly.

It’s like finding a loophole in someone’s instructions and using it to mess things up. This type of
attack doesn’t need a lot of resources—just clever exploitation of the system’s weak points.

3) Protocol attacks:

When computers send and receive data over a network, they follow protocols, which are like rules
or guidelines that ensure everything works smoothly. Think of protocols like traffic rules that tell
cars (data) how to move safely on the road (network).

In a protocol attack, an attacker looks for weak points in these rules or mistakes in how they’re
implemented on the victim’s system. Then, they use these flaws to cause problems.

For example:

 A protocol might say, "Wait for a reply before sending more data." The attacker sends
requests but doesn’t reply, making the system wait indefinitely and stop working.

 The attacker might send fake or incomplete messages that confuse the protocol and make
the victim's system crash or slow down.

4) Unintentional DoS attack:

Sometimes, a website can crash or stop working not because of an attacker but because it
suddenly gets too many visitors at once. This is called an unintentional denial-of-service (DoS)
attack.

For example:
Imagine a small, lesser-known website gets mentioned by a big, popular site in a news story. If
thousands or even millions of people click the link at the same time, the smaller site might not
have enough capacity (bandwidth or server power) to handle all the visitors. It becomes
overwhelmed and stops working temporarily.
It’s like a small cafe that usually serves 10 customers at a time suddenly gets flooded with 1,000
customers. The staff and resources can’t keep up, so no one gets served.

13) Types or Levels of DoS Attacks:

1)A flood attack :

is one of the oldest and simplest types of DoS attacks. Here's how it works:

1. The attacker uses the ping command, which is like sending a "hello" message to a
computer to check if it’s online. Normally, the computer replies with a "hello back."

2. In a flood attack, the attacker sends too many pings, one after another, much faster than
the victim’s system can handle.

3. The victim’s system gets overloaded trying to reply to all the pings and eventually becomes
too slow or crashes.

To pull this off, the attacker usually needs a faster internet connection than the victim so they can
send a huge number of pings quickly.

It’s like someone ringing your doorbell nonstop. You get overwhelmed trying to answer the door,
and eventually, you can’t do anything else.

This attack is easy to launch because it doesn’t need advanced tools, but it’s hard to prevent
completely since pings are a normal part of how computers communicate.

2) Ping of death attack:

When computers communicate over a network, they use a standard rule called ICMP (Internet
Control Message Protocol) to send messages like "There's an error" or "This data can't be
delivered." These messages are usually small and easy to handle.

In a Ping of Death attack, the attacker sends a giant ICMP packet (a message that’s much larger
than what the system can handle). Some computers or operating systems aren’t prepared for such
oversized packets.

What happens next?

 The system receiving this oversized packet might crash, freeze, or reboot because it doesn’t
know how to process it.

 This makes the victim's computer or network unavailable, causing a denial of service (DoS).

It’s like stuffing an oversized package into a mailbox that’s too small. The mailbox breaks, and you
can’t use it anymore.

This attack is no longer common because modern systems are built to handle these oversized
packets safely, but it was a big problem for older computers.
3) SYN attack:

A SYN attack (or TCP SYN Flooding) is like a prank where someone keeps knocking on your door
but never comes inside, so you're stuck waiting for them while ignoring other visitors.

Here's how it works in simple terms:

1. Computers use a "handshake" to start communication, where one sends a SYN (saying,
"Can we talk?"), the other replies with SYN-ACK ("Sure, let’s talk"), and the first sends back
an ACK ("Okay, let’s begin").

2. In a SYN attack, the attacker sends a lot of SYN messages to a server but never responds
with the final ACK.

3. The server waits for each missing response and reserves space in its memory for these
incomplete connections.

4. Eventually, the server's memory gets full, and it can’t handle new connections from real
users.

4) Tear drop attack:

A Tear Drop attack is like sending broken puzzle pieces to someone, but they don't fit together
properly, making it hard for the person to put the puzzle back together.

Here's how it works in simple

5) Smurf attack:

A Smurf attack is like playing a prank where you send a message to a large group of people, asking
them to all reply to someone else, flooding them with responses.

Here's how it works in simple terms:

1. The attacker sends a ping request (like asking, "Are you there?") to a broadcast address,
which means it goes to everyone on the network.

2. Every computer on that network receives the ping and replies back with a response
(saying, "Yes, I'm here!").

3. If there are many computers on the network, each one replies, which causes a massive
flood of replies directed at the target.

4. The target gets overwhelmed with all the ping replies, slowing it down or crashing it, even
though the attacker didn't directly send all those replies.

6) Nuke:
A Nuke attack is like repeatedly sending broken or incomplete puzzle pieces to a computer, making
it struggle to put them together, slowing it down until it eventually stops working.

Here's how it works in simple terms:

1. The attacker uses a modified ping tool to send corrupt or fragmented data packets (like
puzzle pieces that don’t fit).

2. These broken packets confuse the target computer, making it work extra hard to process
them.

3. The computer gets overwhelmed by the constant flood of these broken packets, eventually
slowing down or freezing completely.