Trojans are malware that disguise themselves as legitimate programs to trick users into downloading and installing them. Once installed, they can allow hackers access and perform malicious activities like stealing data. Worms are standalone malware that spread automatically without needing user interaction. Ransomware encrypts users' files and demands payment for their return. Spyware secretly monitors users' online activities through keyloggers, hijacking webcams and microphones, and cracking passwords using dictionary attacks.

1. Trojans, Worms,
Ransomeware and
Spyware
Ethical Hacking

2. What is a Trojan and how they differ from other viruses.
What are Worms?
Today we are going to:
Learning intentions
What is spyware and how are they used

3. What are Trojans?
A Trojan is a piece of malware that is disguised as something else in
order to trick users into downloading and running it.
The Trojan may be disguised as a useful program such as an anti-virus
utility or a computer game, but once downloaded it runs malicious
code.
Unlike viruses, Trojans typically do not self –replicate; instead, they rely
on their disguise to gain access to computer systems. In addition, they
are often discreet programs and do not attach themselves to other

4. What are Trojans?
The name comes from the story about the Trojan war, where Greeks
used deceit to capture the city of Troy. The Trojan horse was a bad
thing disguised as something good in order to trick the Trojans into
inviting it into their city; A Trojan piece of malware tricks users into
downloading providing a backdoor into the system.

5. Backdoor Trojan / Virus
A backdoor Trojan / Virus is a method of accessing a computer system
through indirect or dishonest means.
These can be deliberately created by software manufactures for
legitimate reasons, such as maintenance or support, but they are often
used in cyber crime to access computers.

6. Backdoor Trojan / Virus
A backdoor Trojan gains access to a computer system and then makes
alterations to that system which allows hackers and cyber criminals to
gain access.
This involves disabling a security feature and if successful it could allow
malicious individuals or groups to access all data held and even control
remotely.

7. Worms
Computer worms are similar to viruses in that they replicate working
copies of themselves and can cause the same type of damage.
In contrast to viruses which require the spreading of an infected host
file, worms are standalone software and do not require a host program
or human to help propagate.
To spread, worms either exploit a vulnerable on the target system or
use social engineering to trick users into executing them.
Worms enter the system through a vulnerability in the system

8. Ransomware
Ransomware is a class of malware that encrypts or threatens to delete
your files unless you pay a sum of money to the attacker.
This could be virus, worm or trojan that gains access to your computer
either by exploiting a software vulnerability or by social engineering.

9. Ransomware
The ransomware often encrypts or steals the files held on the computer
and leaves a message with demands and instructions for payment.
In majority of cases the police and security services and unsuccessful in
tracing the criminals or re-gaining access to the data.
Paying the money can often lead to further demands by the criminals.

10. Spyware
Spyware is the term used to describe software that is used to effectively
‘snoop’ on the computer use by individuals.
The following are types of spyware:

11. Spyware - Keyloggers
The purpose of a keylogger is to record the keystrokes a user enters
on their computer. This is useful for gaining information like private
correspondence, usernames and passwords to online accounts, and
even credit or debit card details.
Keyloggers can be hardware or software. Hardware keyloggers are on
a small device that looks similar to a USB flash drive. The device is
plugged in between the keyboard and the computer and records each
keystroke.

12. Spyware - Keyloggers
The device is then collected later.
Software keyloggers do the same thing however they record and send
to the user genuinely over the internet, either in real time on as one
document.

13. Spyware – Webcam / Microphone Hijacks
Webcam hijacks are attacks that allow the perpetrators to turn on the
user’s webcam, without their knowledge and either take snapshots or
record the live feed.
Most modern computers have webcams built into their computers which
uses a light to indicate when it is in use. More sophisticated attacks can
disable this light so the user would have no idea.
Mobile devices such as phones and tables are also susceptible to this
sort of attack.

14. Spyware – Password Attacks
Most computers and online accounts require a username and
password to authenticate account holders, though the trend is now
going towards moving away from passwords as an authentication
method and using various biometric systems such as fingerprints and
retina scanners.
Most common why criminals gain access to password protected
systems is through a Dictionary Attack.

15. Spyware – Password Attacks
Password dictionaries are lists of common passwords that have been
compiled and are available online. Criminals launch a dictionary
attack that tries each password one by one until they gain access.
Using good passwords that are unique and systems that have limited
number of attempts are a way of preventing this.