A computer virus is a program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes.

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17
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4answers
4k views

What is the corrupted image vulnerability? How does it work?

What exactly happens when someone injects malicious binary code into an image file (on Windows)? How is that done?
9
votes
4answers
2k views

Is it safe to serve any user uploaded file under only white-listed MIME content types?

Let's say I develop an application that, Allows any user to upload a file of only white listed mime content type and extensions (word and pdf). Serves those files with the allowed extension and ...
34
votes
2answers
11k views

What malicious things can happen when clicking on links in email?

I've received a spam from one of my friends (well I'm sure he didn't send it). so there's this link, and i'd thought what exactly would be the implications of clicking the link (i've not clicked it ...
14
votes
6answers
6k views

Finding a specific malware sample for malware analysis purposes

I wish to analyze the changes made by a specific virus. For example, Win32.Sality. Where can I get the sample of this, or other similar, malware for testing?
41
votes
8answers
10k views

Should I get an antivirus for my Mac?

There are some people saying that people should use an antivirus software on Mac. And there are thousands of people claiming that Macs don't get viruses (under this term I mean spyware / malware as ...
13
votes
4answers
2k views

How is a worm different from a virus?

In spite of various online articles, I'm a bit unclear on the distinction between a "worm" and a "virus". Two related questions-- Is there a useful and clear distinction here or no? If so, what is ...
9
votes
2answers
15k views

Advice on what to do after being hacked?

After running a system scan earlier today, I found that my computer had been infected by a trojan horse. My reason for running the scan was because Windows kept shutting down and then recovering. ...
38
votes
4answers
18k views

Should I get an antivirus for Ubuntu?

Considering the recent thread regarding anti-virus for the Mac I wonder how many of the arguments put forth are relevant today to Linux systems, specifically Ubuntu. There are no known Ubuntu ...
20
votes
4answers
42k views

How to inject executable, malicious code into PDF, JPEG, MP3, etc.?

I wanted to know if its generally possible to inject executable code into files like PDFs or JPEGs etc., or must there be some kind of security hole in the application? And if so, how would one do ...
22
votes
4answers
6k views

Are popular porn sites more likely to be infected with malware?

I'm trying to help my friend understand this because he believes that since a site is very popular, that it's less likely to infect its viewers because of its security! Is a popular site less likely ...
8
votes
4answers
919 views

Is disabling auto-run enough to protect against malicious code from removable media automatically infecting a machine?

If I block auto-run on a windows machine, is this enough to protect it from malicious code (assuming I don't run any files manually)? Or are there known vulnerabilities that may cause infection?
6
votes
2answers
3k views

Viruses on video cards?

Steve Gibson of Security Now fame claims that viruses can attack a video card and infect it. I assume that he means it can infect the Video BIOS. However I'm skeptical. BIOSes are so numerous and ...
5
votes
2answers
490 views

How might an email do damage merely by being opened?

E.g. http://www.dailymail.co.uk/sciencetech/article-2094982/Threat-new-virus-infected-emails-PC-DONT-open-attachments.html?ito=feeds-newsxml Assuming that the user clicks no links and opens no ...
44
votes
6answers
6k views

Virus Encoded in Video

So I'm not familiar at all with IT Security, but I'm a bit curious about something. I was watching a TV show and at one point, a virus spreads through an office. They investigate and find out that the ...
12
votes
8answers
5k views

Can malware be attached to an image?

I have a small number of employees who use a company computer but these people aren't very tech savvy. They use an email client and a messaging client. I'm pretty sure they wouldn't click on .exe or ...
8
votes
3answers
3k views

Am I protected from USB autorun malware on Windows 7?

As far as I know, the autorun.inf problem (the possibility of automatically executing code when a USB stick is plugged in) was solved through Windows Updates for XP, and on 7 it is no longer possible ...
5
votes
2answers
543 views

What is a Flash drive by download?

I've seen many people saying how some sites can infect your computer without actually clicking anything. They said that it was a "Flash Drive By" and it would use flash to download a file of any kind. ...
4
votes
4answers
1k views

Is it possible to catch a virus on my LAN without clicking on anything?

My unpatched PC running Windows is connected to a network which contains other "infected" computers, can I get infected by viruses without any interaction on my part?
3
votes
3answers
3k views

Can malware physically damage a hard drive?

I recently responded to an incident of supposed malware infection. The symptoms were simply, "My computer freezes at random times." The response ended with replacement of the physical hard drive and ...
5
votes
3answers
28k views

CryptoWall 3 - how to prevent and how to decrypt?

My father's computer is now infected with CryptoWall 3, according to the link below. http://www.bleepingcomputer.com/virus-removal/cryptowall-ransomware-information#CryptoWall Is there a way to ...
3
votes
5answers
1k views

How can I know if my PC is getting infected?

I have installed an antivirus, but as no antivirus is perfect, what can I do to diagnose if my PC is getting infected? For example, keeping a close eye on what programs and tasks run when I turn my ...
2
votes
3answers
828 views

Is it possible for a virus or unknown program to automatically start up a webcam

How can I secure my computer more, knowing these days that there are many websites, especially ones where you don't have to even click before a virus is downloaded straight to your hard-drive. I ...
1
vote
3answers
269 views

Removing a Redirect Virus from Fedora Linux

Despite several attempts listed below certain websites are getting redirected to a certain ad website automatically, out of the blue on linux. When some website starts redirecting to this ad website ...
35
votes
7answers
114k views

How can I watch porn, safely, and not get a virus? (and not infect corporate data also)

I'm part of a small office in the middle of nowhere, and we just got absorbed into a large mega corporation. Sometimes we watch porn, at the office, on company computers, using the company ...
17
votes
2answers
762 views

Is there a real possibility of getting malware by “drive-by”?

I know malware can be gotten by downloading and running stuff, but is there a real possibility of just viewing a webpage or clicking a link and getting one? Assuming using only Firefox / Chrome and ...
20
votes
2answers
4k views

How does a crypter for bypassing antivirus detection work?

I am talking about crypters used to encrypt files like viruses and keyloggers for the sole purpose of bypassing antivirus detection. How do they work?
19
votes
3answers
4k views

How can I tell if I have the citadel virus without downloading an antivirus?

I recently received an e-mail from Virgin Media indicating that I might have the Citadel virus. It obviously sounds like a fake e-mail, but I am almost certain it is genuine, as they had my name and ...
18
votes
7answers
1k views

Why do malware creators use such clever technologies for such silly purposes?

Some days ago I got infected by a malware, probably something new and very clever, as it went in unstopped and no scanning tool was able to detect it afterwards (see this question). It was a ...
17
votes
7answers
861 views

How to deal with a person who gets easily fooled by internet and mail scams?

alternative title: How to deal with a person who has gotten paranoid and doesn't want to go online anymore? A person, who has over the years been scammed many times, by bad spam/fraud emails, and ...
19
votes
4answers
2k views

Are anti-virus companies companies regularly committing software piracy?

As Mikko Hypponen highlighted in a recent tweet, anti-Virus companies collect and store both samples of malicious software and samples of legitimate software: This got me to thinking, what ...
12
votes
5answers
965 views

Detection and analysis of unknown malware

Suppose I have a binary which is suspicious. How can I determine whether it is malicious, and if it is, reverse-engineer how it works and what it does? For example, maybe using static analysis? Are ...
11
votes
5answers
276 views

Security of root terminal (su -) when logged into X

I often log into X as normal user (of course), open terminal and switch to root: su - I have then a terminal owned by user but effectively with root privileges. Are there any security issues in ...
8
votes
6answers
796 views

What is preventing the widespread common use of MAC-type systems?

Overall question what is preventing the uptake of MAC systems such as SELinux/AppArmor in corporate and desktop computing environments? Why don't you think it isn't already widespread? I do not ...
5
votes
7answers
33k views

Scanning for files than have been encrypted by CryptoLocker

I am just asking in case someone has already done the analysis. A customer has a large set of network drives that were mapped to a CryptoLocker infected machine. The infection itself has been treated. ...
8
votes
6answers
13k views

How can I prevent viruses/malware from infecting my flash drive?

I've a pen drive that I carry to the college lab . It seems all the systems in lab is infected. I need to be able to write to the drive, so I can't simply write protect it. Everytime I insert a ...
6
votes
3answers
333 views

How safe are copies of Firefox that are on various Mozilla mirror sites?

If I end up downloading a .dmg or .exe (depending on OS) installer from some mirror site, how can I be sure that a virus or trojan or spyware has not been added? I don't see any mechanism for ...
3
votes
3answers
2k views

Self-Executing Files

I've always been curious about understanding how virus carry out their activities. For that reason, I've read a lot of books and articles about different types of viruses and the way they operate in a ...
2
votes
2answers
69 views

Determining safety of Android APK executable that requires root

On my request, a developer gave me a new version of his Android app to test. The app requires root permissions. I do not know the developer personally. I have no specific reasons to trust or ...
5
votes
1answer
452 views

How antivirus companies create virus defnitions for new outbreaks

This question quite amazes me. I dont understand how antivirus companies get info about the latest viruses. have they installed some kind of filters to monitor the internet traffic ? Or they are ...
4
votes
4answers
2k views

Virus scanner on server

I see lots of people claim virus scanners are unnecessary on a linux server. But if this server accepts files uploaded from users (and lets others download them), does it become worth it to scan the ...
3
votes
2answers
184 views

How to get rid of an Ad bot?

The issue started due to setting up a proxy server on a PC connected to my network. I then realized that all of my devices that connected to the network, including PCs and phones, are all infected by ...
2
votes
3answers
114 views

Can viruses be transfered across incompatible architectures?

I am needing to run scans from one computer/laptop/device to another computer in a protected system. I am worried that plugging in my scanning computer to the protected computer might cause some risk ...
2
votes
2answers
3k views

How to check if a website is sending out a virus?

I'm a webmaster at a company without much knowledge of IT Security. We are running 6 computers connected to a central server that also hosts our website. 3 out of 6 people in the office have gotten ...
1
vote
1answer
2k views

Uploading images safe of XSS, php code and virus

I know that my question has been responded lot of times, but most the responses addresses functions that I don't even use (like use include with images) and that makes me worry because maybe I'm not ...
-1
votes
1answer
136 views

Would this be plausible for a metamorphic virus? Not repeatedly infecting same system

Would this be plausible for a metamorphic virus? When a new generation (for lack of better word) is created it would hard code a random file name, that would be checked to see if the system was ...
6
votes
5answers
7k views

Is it worth it to get paid anti-virus software?

With the rise in cybercrime, I am slightly worried about my computer security. I have been using open sourced anti-virus AVG for years and it has been doing well. Are anti-virus software like Norton ...
5
votes
4answers
642 views

How to keep Mac secure from viruses, malware and keyloggers?

How can I download and install software and make sure that it is not infected with viruses, malware or a keylogger? Also, I heard that Macs "don't get viruses". Is this true? Is it a good practice to ...
5
votes
5answers
1k views

Windows 2003 Enterprise infected by Conficker; post-infection problems continue

I used various tools to remove Conficker, and I pretty much succeeded, but I've had recurring problems afterward. It won't update anymore (with the following error message: 0x800706B5) I tried ...
3
votes
2answers
493 views

How to practically detect current system net traffic?

I know that some viruses or trojans can install rootkits or bootkits to change system's normal behaviour; AFAIK for example filter queries for running processes or even hide active TCP ports. My ...
1
vote
3answers
275 views

How isolated are 2 operating systems on 1 harddisk?

Lets say I have 2 windows dual booting on the same harddrive (windws 7), How isolated are they? I am thinking that there should be up to date antiviruses software on both Windows, and they should be ...