viruses juan arriola cs-100. history computers viruses first appeared with the credit of john von...
TRANSCRIPT
VirusesViruses
Juan ArriolaJuan Arriola
CS-100CS-100
HISTORYHISTORY
Computers viruses first appeared with Computers viruses first appeared with the credit of John von Neumann due to the credit of John von Neumann due to his studies on the self replication of his studies on the self replication of mathematical automata in the 1940’s. mathematical automata in the 1940’s. Then the idea of viruses infecting Then the idea of viruses infecting computers and their programs emerged computers and their programs emerged in the 1970’s leading to the first in the 1970’s leading to the first recorded case of the Brain virus at the recorded case of the Brain virus at the University of Delaware in late 1987.University of Delaware in late 1987.
What is a Virus?What is a Virus?
A computer virus is a piece of software designed A computer virus is a piece of software designed and written to make additional copies of itself and and written to make additional copies of itself and spread, typically without user knowledge or spread, typically without user knowledge or permission. permission. Some viruses display symptoms, and some cause Some viruses display symptoms, and some cause damage to files in the system that have been damage to files in the system that have been infected. infected. Since a virus is code that was not intentionally Since a virus is code that was not intentionally installed by the user, there are no "good" viruses. installed by the user, there are no "good" viruses. When a virus finds itself in a different environment When a virus finds itself in a different environment than that for which it was written, a non-destructive than that for which it was written, a non-destructive virus can become destructive.virus can become destructive.
There are 4 main classes There are 4 main classes of viruses:of viruses:
1.1. Boot-sector virusesBoot-sector viruses
2.2. Program file virusesProgram file viruses
3.3. Multi-partite virusesMulti-partite viruses
4.4. Macro virusesMacro viruses
How Do Computers Become How Do Computers Become Infected?Infected?
1.1. Viruses can be hidden in programs Viruses can be hidden in programs available on floppy disks or CDs, hidden in available on floppy disks or CDs, hidden in email attachments or in material email attachments or in material downloaded from the web.downloaded from the web.
2.2. Once the virus is active on the computer, it Once the virus is active on the computer, it can copy itself to (infect) other files or can copy itself to (infect) other files or disks as they are accessed by the user. disks as they are accessed by the user.
How do they work?How do they work?
Viruses work in a multitude of different ways:Viruses work in a multitude of different ways:
They can damage important operating system filesThey can damage important operating system files
After infecting your computer, they spread After infecting your computer, they spread themselves to other computers by using your themselves to other computers by using your Internet connection when you’re online. Internet connection when you’re online.
They can collect important information about the They can collect important information about the users of the computers the viruses infect and send users of the computers the viruses infect and send it back to the authorit back to the author
How do they work?How do they work?
They can send emails (without you even opening They can send emails (without you even opening your email program) to everyone in your address your email program) to everyone in your address book from you that contain the virus.book from you that contain the virus.
They can also spread through other connections They can also spread through other connections that your computer maintains to the Internet.that your computer maintains to the Internet.
They can produce annoying pop-up They can produce annoying pop-up advertisements (even when you’re not on the advertisements (even when you’re not on the Internet), they can crash websites, and pretty much Internet), they can crash websites, and pretty much anything else you can imagine. anything else you can imagine.
How do I get infected?How do I get infected?
Most viruses infect computers through Most viruses infect computers through application files of some kind (attachment application files of some kind (attachment files with a .EXE or .SCR extension are the files with a .EXE or .SCR extension are the most typical). The user of the computer (you) most typical). The user of the computer (you) has to physically open the application file. has to physically open the application file.
Most viruses come through as an attachment Most viruses come through as an attachment to an email message. However, since 2003, to an email message. However, since 2003, viruses have become more advanced and viruses have become more advanced and can actually infect your computer through can actually infect your computer through open connections to the Internet.open connections to the Internet.
Why do people write them?Why do people write them?
People can write viruses to collect People can write viruses to collect important information (like credit card important information (like credit card numbers) for malicious intent, to see numbers) for malicious intent, to see how many computers they can infect how many computers they can infect and, in some cases, people write and, in some cases, people write viruses to crash websites (like the viruses to crash websites (like the Blaster worm of August 2003 which Blaster worm of August 2003 which was written to crash Microsoft’s was written to crash Microsoft’s website).website).
What are some common What are some common computer viruses?computer viruses?
NetskyNetsky
BlasterBlaster
SobigSobig
MelissaMelissa
LovletterLovletter
ChernobylChernobyl
KlezKlez
NimdaNimda
Lirva Lirva
Viruses NamesViruses Names
NetskyNetskyWin32.Netsky.ABWin32.Netsky.ABWin32.Netsky.ACWin32.Netsky.ACWin32.Netsky.BWin32.Netsky.BWin32.Netsky.CWin32.Netsky.CWin32.Netsky.DWin32.Netsky.DWin32.Netsky.PWin32.Netsky.PWin32.Netsky.QWin32.Netsky.QWin32.Netsky.SWin32.Netsky.SWin32.Netsky.TWin32.Netsky.TWin32.Netsky.WWin32.Netsky.WWin32.Netsky.YWin32.Netsky.Y Msblast:Msblast:Win32.Msblast.AWin32.Msblast.A
BugBear:BugBear:[email protected]@[email protected]@mm
Klez:Klez:[email protected]@[email protected]@[email protected]@[email protected]@mmCodeRed:CodeRed:Win32.IISWorm.CodeRedWin32.IISWorm.CodeRed.F.F
Safe Computing practices!Safe Computing practices!
Anti-Virus softwareAnti-Virus software
ScanScan your computer your computer on a regular basison a regular basis
UpdateUpdate your Anti- your Anti-Virus Software on a Virus Software on a regular basisregular basis
BackupBackup your files on your files on a regular basisa regular basis
Scan & Protect Scan & Protect Floppy DisksFloppy Disks
ScanScan E-mail E-mail AttachmentsAttachments
BewareBeware of E-mail of E-mail Attachments from Attachments from unknown sources unknown sources
Be Be AlertAlert
Resources Cited:Resources Cited:
www.bullguard.comwww.bullguard.com
www.sophos.comwww.sophos.com
www.mcafee.comwww.mcafee.com
http://www.trendmicro.comhttp://www.trendmicro.com