Computer viruses are malicious software designed to disrupt systems, cause data loss, and spread through executable files and networks. Symptoms include slow performance, unwanted pop-ups, and unauthorized emails, while common types include Trojan horses, worms, and email viruses. Protection involves using updated antivirus software, exercising caution with downloads and email attachments, and regularly backing up data.

1. COMPUTER
VIRUS

2. DEFINITION
• Computer viruses aim to disrupt system,cause
major operational issues, and result in data loss
and leakage.
• They typically attach to an executable host
files,which results in their viral codes executing
when a file is opened.
• The code then spreads from the document or
software it is attached to via networks, drives,file
sharing programs, or infected email attachment.

3. Common signs of computer
virus
• System running slower than usual.
• Unwanted pop-up windows appearing on a
computer.
• Computer program unexpectedly close by
themselves.
• Accounts being logged out.
• Mass emails being sent from your Email Account.
• System crashes and computer itself unexpectedly
closing down are common indicators of a virus.

4. Basic
computer
viruses
TROJAN HORSES:Appears
as interesting program file but
when installed it allows
instructions to access and
read your files.
WORMS:Virus that copies and
multiplies itself by using
computer networks and
security flaws.
E-MAIL VIRUS:Use e-mail
message to spread which
allows it to automatically
forward itself to thousands of
people.

6. Characteristics of virus
Computer viruses are malicious software programs created with the intention of
infecting computer systems and causing harm. They are designed to replicate
and spread by attaching themselves to other legitimate files or programs on a
computer or network.
• The main characteristics of computer viruses include:
• 1. Replication: Viruses can make copies of themselves and spread from one
system to another through different means, such as file sharing, email
attachments, infected websites, or removable storage devices.
• 2. Damage or Disruption: Once a virus infects a system, it can cause varying
levels of damage or disruption. This may include corrupting or deleting files,
slowing down system performance, modifying system settings, stealing
personal information, or even rendering a system completely unusable.
• 3. Concealment: Viruses often try to hide their presence to avoid detection by
antivirus software or the user. They may use techniques such as encryption,
polymorphism (changing their code structure), or rootkit techniques to remain
undetected.

7. • 4. Activation: Some viruses are programmed to trigger specific
actions or behaviors under certain conditions. For example, a
virus might activate on a specific date or when a particular file
is accessed, causing its payload to be executed.
• 5. Payload: The payload is the harmful part of a virus that
carries out its intended action. It could be anything from
displaying unwanted messages or images to deleting files or
even launching more severe attacks, such as stealing sensitive
data or gaining unauthorized control over a system.
• To protect against computer viruses, it is essential to have
reliable antivirus software installed and regularly updated. It is
also important to exercise caution when downloading files,
opening email attachments, or visiting unfamiliar websites to
minimize the risk of virus infections. Regularly backing up
important data is another precautionary measure to mitigate
the potential damage caused by virus.

8. Thank you