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Ok, I have this new computer equipped with windows xp, and I have created to user accounts. The first account is for my computer work and storing my private files. The second one is for surfing the net. Now, can any hacker access (have) my private files?
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My hard disk has two partitions. The system is on C:\ . Now if I store my files on D:\ , and go to
My computer (right click) > Manage> Disk management> right click on D > change drive letter or path> remove
Can any one access mess with my files while I’m surfing the net? -
When I download a virus, can the virus affect my computer even with out me excuting the virus (by double-clicking on it)? When does it affect the computer if it’s programmed to immediately damage the computer?
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Can a virus cause phsical damage to a computer?
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Can viruses be embeded in pictures, videos, and other seemingly safe files?
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Is there any way to know for sure that my computer is being hacked?
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That’s a pretty good idea. It makes sense for lots of reasons.
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I have never heard of anyone doing that. I don’t think it would hurt but it sounds like a hassle and overkill. Common sense stuff is better and easier.
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Viruses can come from lots of different places, whatever some evil guy in a basement can think up as novel really. A virus may act right away but usually not. They usually set up some process that may allow your computer to do tasks the virus writer wants like send out spam. A large percentage of viruses don’t actually do anything harmful to your computer. They are just there. They may propagate all over looking for certain conditions they can exploit.
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Never is a strong word but I don’t see how. All the mechanisms I know would require it to have control over system power or something I haven’t heard of one that can do that.
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Yes. Exploiting those types of files is a major mode of virus transmission.
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Not without a virus scanner and a firewall (hardware and/or software) plus some spyware and adware tools on top of that. There are good programs in each of those categories that are free so there is no reason to have them. Avg used to be a good free virus scanner but Avast Free Edition has been upgraded recently and is very good compared to anything out there.
In many cases, malicious persons or programs are not after your documents; they’re after your operating system - either just to break it, or to exploit it so as to send spam emails or skim future keypresses for passwords and credit card numbers. All accounts use the same Windows system files; so an infection on one account can impact the whole computer.
Not by default (at least not by design) - there may be unpatched exploits that permit this, but if anything, it would be more likely to occur that a trojan finds its way onto your machine and acts as a remote access server.
A virus does have to be executed to infect your computer; It used to be the case that the preview pane of certain email clients had vulnerabilities in that it would inadvertently execute a suitably-designed malware, but I don’t think that happens now.
I’ve heard of viruses that can damage computers by rapidly switching a component on and off, causing some sort of voltage spike, but that might be a myth. It’s technically possible that an executed virus could corrupt the flash memory for the BIOS or hard drive firmware, which wouldn’t actually be physical damage, but it might as well be. I don’t think such things are common at all.
There have been exploits for certain video formats, I think.
Probably not for sure, but many common explots are detectable in a variety of ways (system slowdown, detection utilities. firewalls, etc)
You’re clearly quite concerned about these risks; what precautions, if any, have you taken in the form of antivirus software and firewall? What kind of internet connection do you have?
On question 4, it’s not unprecedented, but it depends on your hardware. I’ve heard of two (or possibly three) examples. First, the virus could cause some image to display persistently on your monitor, causing burn-in. This used to be a real risk (screensavers were invented to prevent this happening inadvertantly, hence the name), but I think all modern monitors are designed to not burn in. Second, some hard drives give sufficient control to software that a virus could, in principle, cause a head crash, ruining the disk. Again, I don’t think this is the case for any modern devices. And third, some vira have been known to flash the ROM to something garbage, which isn’t actually physical damage, but will prevent the computer from working, and requires special equipment to fix. I don’t think any current hardware is vulnerable to this, either.
On question 5, any file type at all can have a virus in it, but it’s only a problem if it somehow gets executed. For plain text and JPEG and GIF images, this would be almost impossible (you would have to make an effort to try to execute the virus). Many other file types, however, especially MS Office files, can contain scripts which the computer runs, and which might run a virus.
There have been examples of trojans within JPEG images that begin executing when the image is loaded (taking advantage of holes within the programs that load/display the images).
This is the most important question to me. So, can a virus execute itself? Or does it need me to execute it by double clicking or any other way?
I only have an antivirus program and I’m depending on the system as a firewall. I have a DSL connection.
One final question:
7) Can a malware work without being listed in the processes of Windows Tasks Manager?
It depends on what sort of accounts they are. If your web browsing account is a local Administrator account, then it can see and modify everything on your computer. Set it to limited. I would set your other account to limited, too, and have a password protected administrator account just for installing software.
Excessive - just set the permissions on the D drive to prevent the web browser account from accessing those files. You need to use Safe Mode to do this in XP Home Edition.
Sometimes - there are several drive-by installation scenarios that malware use to install themselves without direct action. If you are NOT admin, they cannot get access to the parts of the system they need to install themselves permanently.
Maybe - answered above. This is not likely to happen now. Most malware these days is focussed on creating a node in a botnet to send spam and attack other servers.
Yes. If the file reader/viewer has a vulnerability then it can be used as an attack vector. Running as a limited user restricts the possible damage.
No, but here are some tips that have served me well for many years -
Use Firewall, Antivirus and Antispyware tools. There are free options that do a good job.
Use FireFox/Thunderbird rather than Internet Explorer/Outlook Express - they are safer.
Use limited accounts - only use password protected Admin accounts for installation/maintenance.
Think about popups/free software offers before you answer/install them. Check software out on the web to see what other people are saying.
Backup your data regularly (weekly/monthly - not once a year).
Yes - they use techniques called root kits to hide themselves from standard views.
Si
Strictly speaking, no program can run itself (it would have to already be running in order to do anything), but there are ways in which malicious programs can infect your computer without you specifically inviting it to do so. Typically, these exploits get patched so as to render them impotent and the classic exploits are generally no longer possible for this reason - this is why it’s a good idea to visit Windows Update regularly and apply updates and service packs.
If you have a router, it will probably contain a built in firewall that will protect you from malicious intrusion from outside. If you only have a DSL modem (usually a little USB device), you would probably benefit from a software firewall - You probably already have the one that comes with Windows as part of the Security Center and for most purposes, this is completely adequate. What it doesn’t do is tell you what’s going on; for that, a third party firewall such as zonealarm would be better.
I think so - because, for example, it could infect a library file that isn’t used all the time.
I think it’s important to put this all in context though; if you take the sensible precautions of:
-Having an up-to-date antivirus program installed
-Using a firewall
-Applying Windows Updates, say, once a month
-Not indiscriminately opening files of unknown source
Then you’ll be just fine.
If you’re considering visiting some of the darker, more dangerous parts of the internet (and it’s there, so why not?), you could always get yourself a ‘Live CD’ version of Linux (a whole operating system that runs directly from CD and doesn’t affect your hard drive) and browse from there - Linux is less vulnerable to common attacks anyway and anything bad that you did happen to come across would simply be discarded when you turn off the PC.
A popular way for Nasty software to get into a system is “Image” or “Video” files that are really executables, as windows hides file extentions by default (The .exe or .jpg parts on the end of the file name). Turning the extensions back on is a good way to protect oneself, particularly if you’re downloading files over peer-to-peer as it seems a common practice on there.
And yes, something can be running and hidden from taskmanager, from the operating system itself. Though I’m not sure if it’s still possible today. I saw it done in Windows a couple years back. A program removed it’s own entry in the process list.
A similar tactic is for the malicious file to be named something like fluffykittens.jpg[lots and lots of spaces].exe - relying on the name being too wide for the column in which it is listed and thus hiding the executable extension.
Ofcourse this means of security is totally scuppered by poor software design, especially in the games market, where many many programs require administrator access to run. Although it’s not limited to just games, I have a high-end scanner here at work which required a complex registry hack to get it to run under a limited account (thank goodness for high-level in-house IT support!).
I have the advantage that I do this for a living. I have only one app that REQUIRES admin access - almost all others (including games) were trivially configured. I have written a few tools of my own to assist in the process. And most games now do conform. Tools that don’t are getting less common - I just installed OpenVPN on a temporary PC (my laptop is dead) and discovered that I no longer needed a privilege elevation hack to make it work - cool.
It can be hard - occasionally awkward. I do like the way Kubuntu does this, but I hear that Vista is pretty clumsy and ineffectual about the whole elevated privileges thing.
The problem is that you can have an easy time, or you can be secure - there is no middle ground. And I prefer secure.
Si