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132

That's a pointless exercise. Most malware scanners match on fragments of binary code (aka virus signatures), and they look for MD5 hashes of known infected code. Unless the virus you wrote has been deployed into the wild, there isn't a chance they'll have your code's exact signatures on file. The scanners that do trigger a match are most likely those ...


98

There are several reasons why Windows is so heavily inflated with anti-virus products. (I am pointing to out-of-the-box (OOTB) experiences). Windows users are, by default, local administrators, so any social engineering done on Windows can usually lead to an execution of software. Modern Linux has users set-up as low-privilege local users. It requires your ...


92

A small trick I learned years ago - lay your email out like this: Short Version Small number of very short succinct points If X, then you need to do this Else, then you need to do that (or don't need to do anything) Long Version or Full Details ...and here you lay out whatever full version you want. 97% of your users will never ...


89

In my experience management doesn't like to listen to clever analogies. Depending on the person they care about the bottom line in dollars or hours of productivity. I would explain: The actual bottom line is that a compromise of our data will cost the company approximately X dollars + Y hours to recover. This is Z% likely to happen given the malware ...


67

I'm afraid your compiled binary will differ a lot from the actual malware that can be found in the wild. Different compilers and command-line flags will produce completely different binaries, and the malware binary may be further optimized/obfuscated using additional tools or even manually. Submitting them your compiled binary is likely to be ...


56

Your answer is pretty OK, but you could explain the ongoing "game" between spammers and spamfilters a bit more. This makes it understandable why some spam always will find its way to the customer. Spam filters try to catch all mail that is spam. Spammers try to create mails that are trusted not to be spam - both by spam filters and by humans. For ...


54

You can install an antivirus if you want. It should not hurt your machine, but don't expect much protection for your system and don't consider yourself entirely safe. The efficacy of antivirus software is very relative, and they're mostly in use to avoid propagate old malware especially if you have Windows machines in your ecosystem. You should expect a ...


51

Most anti-virus vendors advise not to use their products together with those from others. That's not (just) because they fear competition. Live virus-scanners scan files on access. When they notice that a process accesses a file, they try to access it before the process to scan it. They even try to do that when that process is another virus-scanner. When ...


49

There is no clear evidence that third party anti-malware security software (AV software) is more effective than Apple's own security solutions to protect Macs. Rich Mogull on the Mac TidBITS blog explains: Far less malware exists for Macs, but even there we see limited effectiveness across tools. For example, in a recent test by Thomas Reed, even the ...


49

Passwords saved by Firefox are not encrypted (they are encrypted but the key can be read out) until you set a master password. I don't think that this is a bug, but every virus could read those passwords nonetheless


48

No Quarantine is nothing but a place to store the infected/suspicious files. When you quarantine a file it is deleted from the actual place and moved to the quarantine location (to the path that your anti-virus program has for them). This is something like keeping a zombie inside a jail. Obviously it is not a threat as long as you don't open the cage. In ...


41

Antivirus detection is a feature extraction and a classification problem. A great analogy is the 20 questions game where the goal is to identify an arbitrary object by asking 20 seemingly unrelated yes/no questions. The idea behind the game is that each answer would eliminate half of the objects so it is theoretically possible to describe 2^20 (1,048,576) ...


41

The reason for this tends to be historical. There is no reason why a modern desktop Linux should be particularly more resistant to malware when compared to a modern Windows desktop. However there have been many more viruses for Windows than Linux amongst desktop users, which is down to factors such as the number of users of the respective platforms and also ...


39

Let us analyze each one of the techniques you want the AV to protect against: UAC Bypass: Any process in the Windows environment running with the trusted root certificate can turn off the UAC bit of its own process, as well as any process spawned by it. This means that if your malicious code can inject itself into a process running with the trusted cert, it ...


35

I would advise against it. In order to perform its job, an antivirus software has to root itself very deeply inside the system, hooking everything, installing drivers and you-name-it. In order to do so, it ends up using techniques similar to malware authors, which will be flagged as highly suspicious by other products. Even if it's not the case, it is ...


34

should I stick it in my IDE, build it and then send the built version to them That's not a good option. Unless there's some reason to believe that the malware author and you have a dev environment in common that the AV vendor cannot reasonably access, the AV vendor can do this themselves and will if they think it would help. It's highly likely they can ...


34

I would avoid the biological or non-business analogies (unless this is a hospital). Your job is to assess risk, cost, and provide options. Your management's job is to make the decision based on your analysis and advice. Generally, an approach in a tabular format is best. "approach", "likelihood of correcting the problem", "cost" are the minimum needed. ...


32

This is a little long but this exact argument has been rehashed for the last 14 years. I want to put it to bed. I worked for Apple Tech support from 1992-2001 and have been an Apple developer since. So, I have a very good historical view of Apple ecosystem malware security. My conclusion? 3rd party anti-malware software on the Mac is unnecessary and as ...


29

TL;DR: There are many more threat vectors from which a virus may be caught than you might think. Viruses commonly exploit holes in software for which there is not yet an available patch. (Or for which the patch was just recently made available, and therefore is likely to be not yet installed on many computers.) Only real-time monitoring software, such as ...


27

Sure. In Cohen's famous result, he says that a perfect virus detector should emit an alarm if and only if the input program can ever act like a virus (i.e., infect your machine and do damage). Consider the following program: f(); infect_and_do_damage(); where f() is some harmless function, and infect_and_do_damage() is a viral payload that infects your ...


26

Very easy. Didier Stevens has provided two open-source, Python-based scripts to perform PDF malware analysis. There are a few others that I will also highlight. The primary ones you want to run first are PDFiD (available another with Didier's other PDF Tools) and Pyew. Here is an article on how to run pdfid.py and see the expected results; Here is another ...


26

You can drink all the red wine anti-virus you want to try and prevent getting cancer, but once you get that first tumor, more drinking isn't going to help. You need to cut it out and make sure that you get all of it, because if you don't it will come back again. Once you get infected with a virus, the obvious symptoms are an annoyance, but it is what you ...


26

The whole goal of HTTPS is to prevent eavesdropping so that anyone monitoring your web traffic can't see what you're sending. As useful as it is, HTTPS presents a bit of a problem to antivirus software because when you visit sites over an encrypted connection, your antivirus software cannot see what sites you're visiting or what files you're downloading, at ...


26

Bypassing AV and IPS can be done through meterpreter or any other RAT. Most of the time meterpreter is handy because first it is open source and second it is implemented as a reflective DLL which insert itself in the exploited process without touching the disk. AV solutions can be bypassed easily through the Veil Evasion project while reverse_https ...


26

Referring to my answer to this question (before it was migrated): No, scanning the drive without "opening the folder" isn't a secure way to protect against viruses on the drive. It's very risky to insert what you believe to be a compromised USB device into your PC, no matter what AV you have installed. If you desperately need files from the drive (to quote ...


25

I'll answer in the form of an anecdote. Back in 2003, I was working in tech support for a Mac-based organisation. We were essentially a government contractor and, as such, nearly all our money came from sending Microsoft Word documents to the government to document what we had done and what we should be paid for. Someone managed to bring a Word macro virus ...


25

Despite the common wisdom, I would not recommend running anti-virus for two reasons: Anti-virus does not really work. Though it might catch trivial or well-known viruses, it mostly just gives you a false sense of security. Anti-virus can cause problems. In order to function, anti-virus programs have to situate themselves quite low on the computer ...


24

I think the most crucial factor for virus infection of desktop Windows system is, definitely, the culture and discipline of software distribution and installation. While the average Linux user opens the package manager and get the vendor-built software package (and doesn't leave the official repository to find software in 90% cases), the average (non-IT) ...


23

The goal of most malware is to remain active as long as possible. The longer it can collect keystrokes, participate in DDoS attacks, redirect search results, send spam emails, shows popup ads, etc., the more profitable it is for the creator. To reach this goal, it has to be undetected. If a piece of malware infects a machine twice, it may leave the machine ...


23

The main function of a SPAM filter is to block anything that looks like a SPAM. The objective of an anti-virus software is to detect and remove anything that possess the signature of a virus (worms included) based on the virus definition installed. Both programs work differently based on different heuristics. An email that doesn't look like a SPAM may ...



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