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themselves to executable host files and then the code spreads to other documents via networks, drives, file-
sharing programs, or infected e-mail attachments.
The most common signs of a virus attack are:
♦ ♦Slowing down of the computer system
♦ ♦Unwanted pop-up windows appearing on computers
♦ ♦Unexpected shut down of the computer or the system hangs
♦ ♦Unusual error messages are displayed on the monitor
• Worms: A worm is a malicious, self-replicating program that spreads throughout a network without human
assistance. These worms consume large amounts of memory and bandwidth and thus affect the servers,
networks, and the individual systems that they are often overloaded and stop responding.
• Trojan Horse: The Trojan horse is malware that disguises itself as a legitimate program. It is mainly sent as an
attachment in an email or as a free-to-download file. Once downloaded, it performs malicious tasks such as
gaining backdoor access to corporate systems, spying on users’ online activity, or stealing sensitive data.
• Spyware: Spyware as the name itself suggests that this malware secretly records information about a user’s key
logging activities. Spyware could capture credit card/debit card details, e-mail IDs and passwords which help
cyber criminals withdraw money from unknown accounts or access sensitive information which they may use
with malicious intent.
• Adware: It is an unwanted program that is installed without the user’s permission, but generally does not have
any criminal intentions. The main objective of adware is to advertise any product/service. But it slows down the
system considerably.
2. Spam: Spams are unsolicited mails sent mainly with the idea of online business schemes or commercial
advertisements, which are sent in bulk to many recipients at once. They contain many fraudulent schemes which
appear to be lucrative choices for the users but which on opening may encounter malware such as worms, Trojan
Horse, spyware, etc. This would obviously be a threat to our computer systems as well as our user accounts held
online. So, it is very essential for the user to be aware of such spam e-mails.
Methods to separate spam emails from important ones are as follows:
• Using good Anti-Spam and Anti-Virus Software: This is the best way to get rid of spam. It not only marks those
spam emails but also protects the user’s account from various malware, which poses a threat to the computer
system.
• Always be sure about the sender and be careful while accessing his or her email: If we do not recognise
any email id or have some doubts regarding the sender of the email, then we should restrict ourselves from
opening it, as there might be a chance of spam. There are also some ways to recognise a spam email which are
as follows:
♦ ♦Sometimes the email id does not match the name of the company or person who has sent it. For example,
suppose the sender is abc@gmail.com but the name displayed is “Gift from flipkart”.
♦ ♦ There might be spelling mistakes with the e-mail.ID. For example, abc@shopcues.in, here the domain name
should have been shopclues.in.
• Being ignorant about the tempting subjects: Always check the subject carefully before opening it. Sometimes,
the subject might sound very interesting such as “You have won 100000 dollars” or the sender might send some
information on some items that were never ordered. These are definitely the signs of being spam.
• Being alert about bank transactions: Request for updating any personal information in a bank or anything of that
sort. They might also ask the user to update credit card details, or might give a threat of locking the credit card,
etc. Such spam mail should always be handled carefully as they are directly linked to the bank account.
• Also, we should be careful before sharing our e-mail IDs with unknown people.
3. Phishing: Phishing refers to cybercrimes where spam email messages are sent to different people to get personal
information like usernames, passwords, card details, etc. In this case, the sender pretends to be a genuine official/
company whose mails look authentic enough to trick recipients into giving their sensitive personal information.
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