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Computer Viruses
Computer viruses are harmful pieces of software which can reproduce themselves and automatically spread to other computers and networks. Questions about computer virus techniques and specific computer viruses belong here.
5,673 Questions
How does dust and dirt harm computers?
Mostly it builds up on the fans and prevents the system from cooling and will lead to shut downs or unpredictable behavior. Using "dust off" or any other compressed air can you can blow the dust out of all of the fans including any fans on the video card if there is one. There are several fans in a normal computer including,
CPU fan mounted on the actual CPU
case fans mounted on the case (could be severel here too)
video card fans are mounted on the video card itself and can be hard to reach(not all video cards have fans mostly just the top end cards)
Also dust can acumulate on your CD roms optics and will prevent the reading of CD's, any standard CD ROM drive cleaner will work to clean it or you can use a que tip with rubbing alcohol to clean it directly.
What is the most common way to get a virus?
1. E-mail attachment.
2. Lack of firewall on an insecure network.
3. Malicious Web pages.
4. Co-installed with other legitimate but contaminated software.
5. Sometimes products like digital picture frames, MP3 players, flash drives, etc., are pre-infected at point of manufacture.
When a computer system becomes infected with spyware it will be able to monitor and watch the activities of the computer user and record this information. This information relates to aspects such as websites surfed, personal information and web browsing habits.
Spyware can also do more than just monitor activities and take information in that it posesses the ability to cause browser redirecting, can make changes to web security settings, force frequent pop ups to appear and it can also reduce both internet speeds and PC performance.
Anti spyware software has always been the best remedy for removing spyware infections and ensuring that your signature database is constantly updated is critical.
What is a List of computer viruses with their functions?
Computer Virus is a kind of malicious software written intentionally to enter a computer without the user's permission or knowledge, with an ability to replicate itself, thus continuing to spread. Some viruses do little but replicate others can cause severe harm or adversely effect program and performance of the system. A virus should never be assumed harmless and left on a system. Most common types of viruses are mentioned below:
Resident Viruses
This type of virus is a permanent which dwells in the RAM memory. From there it can overcome and interrupt all of the operations executed by the system: corrupting files and programs that are opened, closed, copied, renamed etc.
Examples include: Randex, CMJ, Meve, and MrKlunky.
Direct Action Viruses
The main purpose of this virus is to replicate and take action when it is executed. When a specific condition is met, the virus will go into action and infect files in the directory or folder that it is in and in directories that are specified in the AUTOEXEC.BAT file PATH. This batch file is always located in the root directory of the hard disk and carries out certain operations when the computer is booted.
Overwrite Viruses
Virus of this kind is characterized by the fact that it deletes the information contained in the files that it infects, rendering them partially or totally useless once they have been infected.
The only way to clean a file infected by an overwrite virus is to delete the file completely, thus losing the original content.
Examples of this virus include: Way, Trj.Reboot, Trivial.88.D.
Boot Virus
This type of virus affects the boot sector of a floppy or hard disk. This is a crucial part of a disk, in which information on the disk itself is stored together with a program that makes it possible to boot (start) the computer from the disk.
The best way of avoiding boot viruses is to ensure that floppy disks are write-protected and never start your computer with an unknown floppy disk in the disk drive.
Examples of boot viruses include: Polyboot.B, AntiEXE.
Macro Virus
Macro viruses infect files that are created using certain applications or programs that contain macros. These mini-programs make it possible to automate series of operations so that they are performed as a single action, thereby saving the user from having to carry them out one by one.
Examples of macro viruses: Relax, Melissa.A, Bablas, O97M/Y2K.
Directory Virus
Directory viruses change the paths that indicate the location of a file. By executing a program (file with the extension .EXE or .COM) which has been infected by a virus, you are unknowingly running the virus program, while the original file and program have been previously moved by the virus.
Once infected it becomes impossible to locate the original files.
Polymorphic Virus
Polymorphic viruses encrypt or encode themselves in a different way (using different algorithms and encryption keys) every time they infect a system.
This makes it impossible for anti-viruses to find them using string or signature searches (because they are different in each encryption) and also enables them to create a large number of copies of themselves.
Examples include: Elkern, Marburg, Satan Bug, and Tuareg.
File Infectors
This type of virus infects programs or executable files (files with an .EXE or .COM extension). When one of these programs is run, directly or indirectly, the virus is activated, producing the damaging effects it is programmed to carry out. The majority of existing viruses belong to this category, and can be classified depending on the actions that they carry out.
Companion Viruses
Companion viruses can be considered file infector viruses like resident or direct action types. They are known as companion viruses because once they get into the system they "accompany" the other files that already exist. In other words, in order to carry out their infection routines, companion viruses can wait in memory until a program is run (resident viruses) or act immediately by making copies of themselves (direct action viruses).
Some examples include: Stator, Asimov.1539, and Terrax.1069
FAT Virus
The file allocation table or FAT is the part of a disk used to connect information and is a vital part of the normal functioning of the computer.
This type of virus attack can be especially dangerous, by preventing access to certain sections of the disk where important files are stored. Damage caused can result in information losses from individual files or even entire directories.
Worms
A worm is a program very similar to a virus; it has the ability to self-replicate, and can lead to negative effects on your system and most importantly they are detected and eliminated by antiviruses.
Examples of worms include: PSWBugbear.B, Lovgate.F, Trile.C, Sobig.D, Mapson.
Trojans or Trojan Horses
Another unsavory breed of malicious code are Trojans or Trojan horses, which unlike viruses do not reproduce by infecting other files, nor do they self-replicate like worms.
Logic Bombs
They are not considered viruses because they do not replicate. They are not even programs in their own right but rather camouflaged segments of other programs.
Their objective is to destroy data on the computer once certain conditions have been met. Logic bombs go undetected until launched, and the results can be destructive.
Hope i helped!
How can you fix a computer virus on your computer?
Depending on what Anti-Virus software you use will tell you where the virus is and also delete it and store it away in a vault. AVG one of the well known and partly free softwares that can be downloaded locates and can delete the virus. Hope this answers your question.
What are effects of computer virus?
complete take over of your computer
complete wipe out of hard drive
pilferage of:
username
passwords
address book contact list
ANY number [ Soc. Sec.,Bank Pin,ect ] copied and compromised
loss of bank account
loss of all financial accounts
it was created by AMA university Student onLy. . . .
That's a very broad set of questions, but I'll give a small explanation.
The Processor is considered the computers brain. All tasks have to run through it. When looking at a processor you have to look at the speed (in Ghz, the higher the better), the cache (in MB, the higher the better), and how many cores it has (most nowadays have at least 2, the more the better.) You can also find the core size in mm^2. The LOWER the core size, the better in general. Smaller cores tend to be cooler and use less electricity, allowing them to be clocked at higher speeds.
For most people the biggest speed increase comes from more RAM. RAM basically holds information until the processor can get to it. RAM can be in either Megabytes (MB's) or Gigabytes (GB). 1 Gigabyte is equal to 1024 Megabytes. The most common RAM sizes are 256 MB (Fairly rare nowadays), 512 MB, 1 GB, and 2 GB. Again, the higher the better, meaning you'd want as many GB's as possible. 1 GB is fairly standard in newer computers, and a lot of them will have 2 or even 4 depending on the price range. They can go higher than that, but most don't.
You can get into more details about RAM, but for beginners the most important thing to know is that more RAM is better.
The Hard Drive is what stores all the information on the computer. Most hard drives are Mechanical hard drives, which are the slowest kind available right now but are a ton cheaper than faster drives and can hold far more information. When checking the Hard Drive in terms of looking for speed, the higher the RPM's, the faster it will be. The Cache is also important, the higher the better (will be anywhere from `8 MB-64 MB probably)
If you're into gaming, the graphics card has the biggest effect on how fast games can run. Graphics cards are a lot trickier though. The core size on graphics cards matters more than on processors, because there are a lot of them out there and of a couple different sizes. Again, the smaller the core size (sometimes called the "die" size), the better.
For graphics cards there are also several speeds that need to be checked. The memory on it will have it's own speed, as well as the core clock, and the shader clock. For all of these, the higher the better.
And lastly, how much memory the graphics card has needs to be checked. In general anything over 512 MB should be fine, and most now have 1 GB. Anything over 1 GB is usually excessive and not needed, so don't feel like you have to spend a lot more money on a 2 GB version of the same card.
That's the basics, but keep in mind better looking specs don't necessarily always mean better performance, computer parts can be tricky to judge if you don't know what you're doing. Shop around, and try to read reviews and comments on any part you're thinking about getting. A simple google search of the component will bring you tons of both.
What is the basic purpose of computer virus?
Computer viruses are used by hackers for several reasons. Some viruses created as a way of showing off to peers or getting a job. "Hackers" will use viruses as a way of getting to attention of a software developer or security firms. They will create a virus that exploit a bug as a way of getting attentions.
Other viruses are used to gain personal wealth. Viruses will take control of a computer in such a way to exploit digital ads or affiliate programs.
In resent years viruses have been used for cyber warfare. Computers infected with malware are used to send bogus data to government servers in order to make them fail. This was used during the January 2011 revolution in Egypt as a way of slowing down the police.
What are the different types of malicious codes in computers?
Resident Viruses
This type of virus is a permanent which dwells in the RAM memory. From there it can overcome and interrupt all of the operations executed by the system: corrupting files and programs that are opened, closed, copied, renamed etc.
Examples include: Randex, CMJ, Meve, and MrKlunky.
Direct Action Viruses
The main purpose of this virus is to replicate and take action when it is executed. When a specific condition is met, the virus will go into action and infect files in the directory or folder that it is in and in directories that are specified in the AUTOEXEC.BAT file PATH. This batch file is always located in the root directory of the hard disk and carries out certain operations when the computer is booted.
Overwrite Viruses
Virus of this kind is characterized by the fact that it deletes the information contained in the files that it infects, rendering them partially or totally useless once they have been infected.
The only way to clean a file infected by an overwrite virus is to delete the file completely, thus losing the original content.
Examples of this virus include: Way, Trj.Reboot, Trivial.88.D.
Boot Virus
This type of virus affects the boot sector of a floppy or hard disk. This is a crucial part of a disk, in which information on the disk itself is stored together with a program that makes it possible to boot (start) the computer from the disk.
The best way of avoiding boot viruses is to ensure that floppy disks are write-protected and never start your computer with an unknown floppy disk in the disk drive.
Examples of boot viruses include: Polyboot.B, AntiEXE.
Macro Virus
Macro viruses infect files that are created using certain applications or programs that contain macros. These mini-programs make it possible to automate series of operations so that they are performed as a single action, thereby saving the user from having to carry them out one by one.
Examples of macro viruses: Relax, Melissa.A, Bablas, O97M/Y2K.
Directory Virus
Directory viruses change the paths that indicate the location of a file. By executing a program (file with the extension .EXE or .COM) which has been infected by a virus, you are unknowingly running the virus program, while the original file and program have been previously moved by the virus.
Once infected it becomes impossible to locate the original files.
Polymorphic Virus
Polymorphic viruses encrypt or encode themselves in a different way (using different algorithms and encryption keys) every time they infect a system.
This makes it impossible for anti-viruses to find them using string or signature searches (because they are different in each encryption) and also enables them to create a large number of copies of themselves.
Examples include: Elkern, Marburg, Satan Bug, and Tuareg.
File Infectors
This type of virus infects programs or executable files (files with an .EXE or .COM extension). When one of these programs is run, directly or indirectly, the virus is activated, producing the damaging effects it is programmed to carry out. The majority of existing viruses belong to this category, and can be classified depending on the actions that they carry out.
Companion Viruses
Companion viruses can be considered file infector viruses like resident or direct action types. They are known as companion viruses because once they get into the system they "accompany" the other files that already exist. In other words, in order to carry out their infection routines, companion viruses can wait in memory until a program is run (resident viruses) or act immediately by making copies of themselves (direct action viruses).
Some examples include: Stator, Asimov.1539, and Terrax.1069
FAT Virus
The file allocation table or FAT is the part of a disk used to connect information and is a vital part of the normal functioning of the computer.
This type of virus attack can be especially dangerous, by preventing access to certain sections of the disk where important files are stored. Damage caused can result in information losses from individual files or even entire directories.
Worms
A worm is a program very similar to a virus; it has the ability to self-replicate, and can lead to negative effects on your system and most importantly they are detected and eliminated by antiviruses.
Examples of worms include: PSWBugbear.B, Lovgate.F, Trile.C, Sobig.D, Mapson.
Trojans or Trojan Horses
Another unsavory breed of malicious code are Trojans or Trojan horses, which unlike viruses do not reproduce by infecting other files, nor do they self-replicate like worms.
Logic Bombs
They are not considered viruses because they do not replicate. They are not even programs in their own right but rather camouflaged segments of other programs.
Their objective is to destroy data on the computer once certain conditions have been met. Logic bombs go undetected until launched, and the results can be destructive.
See related link for source.
What creates restore points at regular intervals and just before you install software and hardware?
System Protection
Not sure but you can run the below steps to see what it is
You need to run these 4 essential steps to remove all the spyware on your computer.
1. Run Malwarebytes Anti-Malware
2. Run the anti spyware removal programs spybot
3 Run Superantispyware
4. Run a complete scan with free curing utility Dr.Web CureIt!
Use Mozilla firefox or the google chrome browsre for browsing unsafe websites
Does java give your computer a virus?
Java applications operate within a form of virtual machine or sand box, protecting your computer from the operations performed by the executed code... unfortunately, there are ways around every system, and you must always make sure that you run Java applets only from trusted sources.
Note: Java and Javascript are not the same thing, and Javascript can more easily be used to compromise your privacy and security without your knowledge.
Why scan for computer viruses?
You should scan for computer viruses because they can be harmful to your computer and your own personal information that you have stored on your PC. The most common viruses known as Trojans and worms can steal confidential information from your computer. You can get viruses only by clicking in on a website, and you should therefore be careful with trusting unknown websites and you should scan your computer for viruses often.
2) Choose Tools and select "Folder options"
- Click on "View" tab, select "Show Hidden files and folders" and uncheck "Hide Extention...."
- Click on "Hide protected operating system files" (these selections are important to find the files you need to delete)/
- Click "OK."
3. Open Windows Task Manager (ctrl-alt-del) and select the "Processes" tab
- Click on "Image name" to sort the list
- Find "wscript.exe" and click on "End Process" (if there is more than one process with that name you have to end all of them)
- Close Windows Task Manager.
4. Click on Start and select "Search" and search for "autorun.inf" (search the computer)
- Delete all the files that contain the text MS32DLL.dll.vbs (the virus) by pressing Shift+Delete. (There obviously should not be Autorun.inf in the C: root).
5. You will also delete the virus from the system (%homedrive%:\WINDOWS\ MS32DLL.dll.vbs) by pressing g Shift+Delete.
6. Next you have to edit the Register. (Please not that you have to be very careful in the Registry tools; certain mistakes in the Registry can crash your computer)
- Click on "Start" and select "Run" and type in "Regedit" and press "Enter".
- Select HKEY_LOCAL_MACHINE --> Software -->Microsoft -->Windows --> Current Version --> Run.
- Find "MS32DLL" and delete that entry.
6. Select HKEY_CURRENT_USER --> Software --> Microsoft --> Internet Explorer --> Main. There you find Window Title "Hacked by Godzilla" and you should delete that entry. You can close the Registry now.
7. Click on Start --> Run and type in "gpedit.msc" and press "Enter."
-- Open "Group Policy": select User Configuration --> Administrative Templates --> System --> and there you will double click on "Turn Off Autoplay"
- In the window there you should select "Enabled" and select "All drives" (they say in a certain Thai website that select all turn of Autoplay will be safer for not getting viruses). Now you can close the Group Policy.
8. Click on Start --> Run and type "msconfig" and press "Enter".
- Open "System Configuration Utility".
- Click on "Startup" tap
- Find the file MS32DLL, choose Enable All, then uncheck"MS32DLL"
- Click Apply and then OK to close
- Exit the "System Configuration Utility" and select "Exit Without Restart" when prompt.
9. After this, double-click on My Computer and select "Tools" and "Folder Options" and "View" tap to change back there.
- select "Hide Extention..." and "Hide protected operating system file" and "Don't show hidden files and folders".
- Empty the "Recycle bin" and "Restart" your computer.
Extended Solution:
After you have deleted all these Autorun files, if your drives still do not want to open with a left click:
Start the Registry editor: Start->Run "regedit"
or alt-ctrl-del, File->New Task... "regedit"
Navigate to:
HKEY_CLASSES_ROOT\Drive\shell
- If there is a folder: HKEY_CLASSES_ROOT\Drive\shell\open
Delete it.
There should only be Drive\shell\find and maybe Drive\shell\cmd, but if you see Drive\shell\open, delete it.
- Make sure that when in HKEY_CLASSES_ROOT\Drive\shell\, the (Default) key on the right hand window should have a value of "none":
Name: (Default), Type: REG_SZ, Value: none
If your computer is still not fixed, here is a complete registry dump of what the HKCR\Drive\ registry path should look like, along with the HKCR\Directory\ path as well:
Note: you can copy the below lines into a text editor (notepad) and save it as "drivefix.reg" and double click it. All the values below will be entered into the registry, overwriting existing values. But values which do not appear here are not affected.
Note: The @ sign is the name of the (Default) value for each directory/key in in the registry.
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\Drive]
@="Drive"
"EditFlags"=hex:d2,01,00,00
[HKEY_CLASSES_ROOT\Drive\DefaultIcon]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\ 00,5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,73,00,68,00,\ 65,00,6c,00,6c,00,33,00,32,00,2e,00,64,00,6c,00,6c,00,2c,00,38,00,00,00
[HKEY_CLASSES_ROOT\Drive\shell]
@="none"
[HKEY_CLASSES_ROOT\Drive\shell\find]
"SuppressionPolicy"=dword:00000080
[HKEY_CLASSES_ROOT\Drive\shell\find\command]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
00,5c,00,45,00,78,00,70,00,6c,00,6f,00,72,00,65,00,72,00,2e,00,65,00,78,00,\
65,00,00,00
[HKEY_CLASSES_ROOT\Drive\shell\find\ddeexec]
@="[FindFolder("%l", %I)]"
"NoActivateHandler"=""
[HKEY_CLASSES_ROOT\Drive\shell\find\ddeexec\application]
@="Folders"
[HKEY_CLASSES_ROOT\Drive\shell\find\ddeexec\topic]
@="AppProperties"
[HKEY_CLASSES_ROOT\Directory]
@="File Folder"
"AlwaysShowExt"=""
"EditFlags"=hex:d2,01,00,00
"InfoTip"="prop:DocComments"
[HKEY_CLASSES_ROOT\Directory\Background]
[HKEY_CLASSES_ROOT\Directory\Background\shellex]
[HKEY_CLASSES_ROOT\Directory\Background\shellex\ContextMenuHandlers]
[HKEY_CLASSES_ROOT\Directory\Background\shellex\ContextMenuHandlers\New]
@="{D969A300-E7FF-11d0-A93B-00A0C90F2719}"
[HKEY_CLASSES_ROOT\Directory\DefaultIcon]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
00,5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,73,00,68,00,\
65,00,6c,00,6c,00,33,00,32,00,2e,00,64,00,6c,00,6c,00,2c,00,33,00,00,00
[HKEY_CLASSES_ROOT\Directory\shell]
@="none"
[HKEY_CLASSES_ROOT\Directory\shell\find]
"SuppressionPolicy"=dword:00000080
[HKEY_CLASSES_ROOT\Directory\shell\find\command]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
00,5c,00,45,00,78,00,70,00,6c,00,6f,00,72,00,65,00,72,00,2e,00,65,00,78,00,\
65,00,00,00
[HKEY_CLASSES_ROOT\Directory\shell\find\ddeexec]
@="[FindFolder("%l", %I)]"
"NoActivateHandler"=""
[HKEY_CLASSES_ROOT\Directory\shell\find\ddeexec\application]
@="Folders"
[HKEY_CLASSES_ROOT\Directory\shell\find\ddeexec\topic]
@="AppProperties"
HERE'S A SHORTER APPROACH:
- Install "unlocker" from FileHippo.com
- Double-click on My Computer on Desktop.
Choose Tools and select "Folder options"
- Click on "View" tab, select "Show Hidden files and folders" and uncheck "Hide Extention...."
- Click on "Hide protected operating system files" (these selections are important to find the files you need to delete)/
- Click "OK."
- Search for the the file autorun.inf.
- Delete it. It will go to the Recycle Bin.
- Open Recycle Bin. Delete autorun.inf.
- Go to C:\RECYCLER. The search you previously performed will show you what folder where the autorun.inf is. Right click the folder and click Unlocker. Choose unlock, then delete.
- If it's still present in the C:\RECYCLER, repeat the process with the Unlocker until the file/folder is gone.
Go to http://devterch.com/blog/?p=31 they have a tool that you can use and you do not have to be a techie person. The problem with some of these answers is that they require technical people to be able to fix the issues.
http://devterch.com/blog/?p=31
By Khalid Betani
Most of the spyware used today is fairly innocent as it is most commonly used to monitor Internet habits in order to send out target advertisements. Spyware is also commonly found in conjunction with adware and can be harmless. However, there are some types of spyware that can be used to monitor much more than just your online surfing habits. Spyware is capable of monitoring information about other things like, email addresses, passwords, web pages you visited, hard drive information, and credit card information.
The most dangerous part about spyware is that your information can be monitored and sent to third parties without your knowledge. Which means that any information that spyware can get to, can be sent anywhere else. Can you see the dangers in personal and private information getting into the wrong hands? It's for this reason alone that if spyware is found on your computer you should immediately remove it; you have no idea where or who it can go to.
When was the first antivirus invented?
Norton is the leader in security software for your computer with more PC Magazine Editor's choice awards than any other security company. Start a free trial and protect your PC today!
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How can the risks of installing or upgrading software can be minimised?
1.viruses ( can come together with the software),
2. computer crushing,
3.system instability,
4.you computer becoming slow ( program uses up alot of resources e.g space and RAM),
5.harking ( malware can be sent together with the software.)
just to mention a few.
Whata is the fullform of antivirous?
That is the full form - it is neither an abbreviation nor an acronym.
An anti-virus program is one which is used to remove existing viruses or to prevent them from infecting a computer in the first place.
sometimes, yeah, you should never trust a proper site or an add, if you click on something that says on the hyperlink double click then that means what you have clicked on is most likely a virus. If however, you do go on it just click the red X in the right hand corner. thanks.
The command searches for and replaces corrupted system files?
The command ____ searches for and replaces corrupted system files
Answer: sfc /scannow
A logic bomb is a type of malware designed to execute when a certain event or program is executed. Logic bombs run in memory so that they can constantly detect whether the event needed for them to deliver their payload is true.
What are some examples of boot sector viruses?
Parity Boot is an example of boot sector virus.
This virus's payload displays the message PARITY CHECK and freezes the operating system, translating the computer useless.
