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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42
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6answers
3k 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 ...
28
votes
2answers
6k 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 ...
21
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2answers
647 views

Cohen's problem

Fred Cohen determined theoritically that viral detetction is an undecidable problem. Can anyone provide an intuitive reasoning for that? Background Fred Cohen experimented with computer viruses ...
20
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6answers
3k views

Malicious Links that Respond to Browsers but not curl or wget

There are some emails with links to people's cracked websites with a malware download Like this kind of email: fake DHL pack station email ... the links often take the form of: http:// ...
19
votes
4answers
25k 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 ...
19
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4answers
1k 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 ...
18
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2answers
3k 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?
18
votes
3answers
859 views

Are older viruses removed from virus definition files?

Antivirus software receives constant updates in the form of virus definition files, containing the patterns used to identify viruses. It is a feature present on most (if not all) major AV for at least ...
16
votes
5answers
909 views

Why would a virus writer bother to check to see if a machine is infected before infecting it?

I was looking at the tripartite structure of a virus, and it seems to check to see if a computer is infected before infecting it with the virus. Would this be an attempt to use files that are already ...
16
votes
6answers
577 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 ...
16
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4answers
2k 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?
14
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2answers
530 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 ...
13
votes
6answers
1k 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?
13
votes
4answers
969 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 ...
13
votes
6answers
886 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 ...
12
votes
3answers
3k views

What file formats are known to be unsafe?

I recently found out pdf's can contain viruses, and from the impression I got its more than a buffer overflow error (I heard it may visit urls automatically but the person sounded unsure) What are ...
11
votes
5answers
751 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
2answers
461 views

Could once infected machine be ever trusted again?

I'm just about to switch to a new SSD drive, so I figured it's a good occasion for a really, really fresh start. I reconsidered every installed piece of software, uninstalled lots of crap ...
10
votes
6answers
2k views

Can viruses actually inject their code in other processes?

Can a virus really inject its own code into a process so it stays on your computer permantly? The only way to actually remove it is to reinstall your OS. My question is how can it do that without ...
9
votes
8answers
2k 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
4answers
719 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?
8
votes
3answers
3k views

Do I really need an Anti-Virus software if I'm careful about where I browse?

A friend told to me the following: I don't use Anti-Virus software at all, I am just careful about where I go and what I click on. I've also heard this from other people as I've repaired their ...
8
votes
3answers
2k 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 ...
8
votes
3answers
405 views

Can I use the same keyboard on both my infected and non-infected computers?

I have a computer which is virus infected. Can I use the same keyboard on both it and a "safe/clean" computer without fear? Keyboards these days seem to come with built in software and thus must ...
8
votes
2answers
7k 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. ...
8
votes
6answers
676 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 ...
7
votes
7answers
6k views

how to protect my USB stick from Viruses

I repair a lot of computers with viruses, malware, and what not, and I have one problem that I am struggling to find a solution for. Whenever I connect my USB stick that has the tools I need for the ...
7
votes
2answers
6k views

Is Buzzdocks a security threat?

A BuzzDock toolbar suddenly appeared in my Chrome browser. I definitely did not install it nor do I remember installing any crapware. It is not unknown to the internet community (Example 1, Example ...
7
votes
4answers
10k views

Security issues with allowing Dropbox installations on client PC's in our organisation

Does anyone know if there is any good reasons not to allow Dropbox installations on our client PC's? All the PC's have antivirus installed and running. I know it is an additional attack vector to ...
7
votes
2answers
819 views

Recently had a virus, can I use backed up files on clean system?

I had to reinstall my OS (windows) recently due to a virus. I backed up my source files onto a flash drive. How can I get to those files without problems? I know flash drives can have nasty things in ...
6
votes
6answers
8k 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
4answers
439 views

Would running VMs inside of VMs be a more secure way to study viruses, etc?

I was reading this post on SuperUser, and it made me wonder about security. I've read somewhere else that some viruses/malware/whatever CAN break outside of a VM... and then infect the host OS. BUT, ...
6
votes
3answers
614 views

How effective is something like Deep Freeze against boot sector infections?

I work for an embedded system manufacturer and on our older generation systems, which are powered by Windows Embedded, a number of customers have been experiencing virus infections. Due to the real ...
6
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2answers
2k 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 ...
6
votes
4answers
543 views

Is there any chance PHP developers themselves implement backdoors in PHP core?

This is not a concern that I personally have,no! In my job environment I've heard from programmers and non programmers that PHP developers always put secret backdoors in PHP that no one has access to ...
6
votes
3answers
254 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 ...
6
votes
3answers
4k views

Is it possible for a phishing link to install a major virus on a Mac?

My girlfriend recently had her university MS Exchange account hacked. The attacker took over her email account and started using it to send thousands of spam emails. After a while, her email account ...
6
votes
2answers
184 views

How serious is a local virus in terms of network security

I work at a company in the U.S. My colleague got a notification on his machine of a possible virus (through the virus scanner that is installed by default on all machines). He called up the tech ...
6
votes
3answers
352 views

Firewall says that a program that I'm developing is trying to connect to the Internet

I'm seriously confused about this, since the program is entirely developed by myself and has no means/functionality to connect to any network/the internet whatsoever. I'm a software engineer but not ...
6
votes
3answers
438 views

Malware nomenclature

If there a generally agreed upon naming convention for types of malware/virus? For example, are there agreed upon terms for virus, trojan, worm and the like? If one exists could someone explain it or ...
6
votes
2answers
212 views

What implications does IPv6 have for internet worms and script kiddies?

Though IPv6 is not here yet it one day we will all lose our familiar IPv4 addresses and be communicating over the internet solely with IPv6 addresses. What interests me is the implications this has ...
6
votes
2answers
280 views

Statistics on purposes of viruses/malware

Are there any resources that analyze the purpose or goal or the major viruses/malware out in the wild today? For example, what percentage are used to construct botnets (for DDoS or something else)? ...
6
votes
2answers
193 views

Process authentication for Linux

Is there any possibility to authenticate a running process in Linux to be sure that this is the original/right one? I know that an Linux operating system is only that secure like the way you use it. ...
5
votes
6answers
4k views

Can i get 100% protection from virus by using Deep Freeze?

I have recently installed an application called 'Deep Freeze' that works by "freezing" the state of an operating system and working off delta disks. Rebooting deletes the deltas and reverts back to ...
5
votes
5answers
840 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 ...
5
votes
4answers
937 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 ...
5
votes
6answers
560 views

How can a novice find proof of a system compromise?

I am almost certain a colleague has installed a keylogger on my system. I am totally new to IT security, but have substantial linux / windows / programming experience. The system I believe is ...
5
votes
2answers
2k views

Virus detection with Process Explorer

Can Process Explorer ( Windows apparently) detect a virus? Is it even possible?
5
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2answers
949 views

Why did Apple think OS/X was virus proof?

In such articles as this one at Examiner.com, we see that Apple had long "advertised" the immunity of its desktop OS to viruses. It had to dilute that assertion when the Flashback virus appeared. ...
5
votes
2answers
446 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 ...