network viruses

8/7/2019 network viruses

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The most common include:Viruses, worms, and Trojan horses

IntrudersSpyware and adwareZero-day attacks(zero-hour attacks)

Denial of service attacks


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What are Computer Viruses???

It is a computer program that can copyitself and infect a computer without

permission or knowledge of the user.


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Some viruses are programmed to damagethe computer by damaging programs,deleting files, or reformatting the harddisk.

Others are not designed to do any damage,but simply replicate themselves andperhaps make their presence known by

presenting text, video, or audio messages.


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Network Virus

Logic BombsBoot Virus(Disk Killer & Stone virus)Multipartite Virus(Invader, Flip & Tequila)Macro Virus(DMV, Nuclear)Trojan horseWormsProgram virus(Sunday, Cascade)


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An intruder is somebody ("hacker" or

"cracker") attempting to break into ormisuse your system


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Trojan horse programs Back door and remote administration

programs Denial of service Being an intermediary for another attack Unprotected Windows shares Mobile code (Java/JavaScript/ActiveX) Cross-site scripting Packet sniffing


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It is the art of detecting intruders behind

attacks as unique persons.

Intruder Detection Systems try to detectwho is attacking a system by analyzing his

or her computational behavior or biometricbehavior.


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Keystroke Dynamics (keystroke patterns, typing pattern,typing behavior)

Patterns using an interactive command interpreter: Commands used Commands sequence Accessed directories Character deletion

Patterns on the network usage: IP address used

ISP

Country City

Ports used TTL analysis Operating system used to attack Protocols used Connection times patterns


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Spyware is a type of malware

Spyware programs can collect various types ofpersonal information,

Spyware is known to change computer settings,


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Come bundled with other software

Web browser

W

eb Sites


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CoolWebSearch,

Internet Optimizer

Hunt Bar, aka Win Tools or adware Websearch

Zango

Zlob Trojan, or just Zlob


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It is a computer threat that tries to exploit

computer application vulnerabilities that areunknown to others or undisclosed to thesoftware developer.


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An attacker attempts to prevent users fromaccessing information or services.

By targeting your computer and its networkconnection, or the computers and network of thesites you are trying to use, an attacker may be

able to prevent you from accessing email,websites, online accounts (banking, etc.), or otherservices that rely on the affected computer.


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An attacker may use your computer to attackanother computer.


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Not all disruptions to service are the result of aDoS. There may be technical problems with aparticular network, or system administrators.

The following symptoms could indicate a DoS orDDoS attack: unusually slow network performance (opening files or

accessing websites) unavailability of a particular website inability to access any website dramatic increase in the amount of spam you receive in

your account


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Spamming

What is spam?

Where does it come from?

How much of a problem is spam?

What can we do to stop or minimize spam comingto your computer?


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Experts believe that up to 90% of all email isnow generated by spam robots.

In 2007, for the first time, the total of spamemails surpassed genuine emails: 10.8 trillionto 10.5 trillion.


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Spam can be used to spread computer viruses,Trojan horses or other malicious software. Theobjective may be identity theft or fraud.

Some spam attempts to capitalize on human greedwhilst other attempts to use the victims'inexperience with computer technology to trick

them, eg, phishing.


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BAD FOR YOU:

Wastes bandwidth and YOUR valuable downloadallowance

Wastes YOUR time dealing with it

May contain malware than can infect YOUR

computer

May cost YOU money if you get tricked into givingout sensitive information


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BAD FOR BUSINESS:

Spam affects productivity, i.e., wastes time and,in business, TIME IS MONEY.

In Australia, the time and bandwidth lost to spamis estimated to cost business $2 billion a year.

In the US, a national survey in 2004 found that

workers spend 2.8 minutes a day deleting spam ata cost to business of $21.6 billion p.a. in lostproductivity.


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Spam can be categorized into two main types:

Emails that try to sell you something, e.g.

Viagra or a fake Rolex watch, orEmails that try to steal your confidential or

personal information, eg online banking logindetails, credit card details, or social securitynumber (in the US).


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The type of spam that tries to trick you, in orderto steal your personal information, is also knownas phishing.

The outcome to you can be very costly you canlose a lot of money through fraudulent use of youronline identity by cyber criminals.


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case study


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Google case study


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Documents

network viruses