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Questions tagged [malware]

Malware is any software application which subverts the will of the legitimate owner of a computer, by means of force or subterfuge, with or without personal or monetary gain on the part of the creator.

242
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10answers
81k views

How is the “WannaCry” Malware spreading and how should users defend themselves from it?

There's a new strain of attacks which is affecting a lot of systems around the world (including the NHS in the UK and Telefonica in Spain) which is being called "WannaCry" amongst other names. It ...
195
votes
10answers
23k views

What should you do if you catch encryption ransomware mid-operation?

You boot up your computer one day and while using it you notice that your drive is unusually busy. You check the System Monitor and notice that an unknown process is using the CPU and both reading and ...
175
votes
11answers
30k views

Search for military installed backdoors on laptop

My laptop was confiscated by the military institute of my country and they made me to give them all my passwords (I cannot tell you the name of my country). They did not give it back to me for one ...
163
votes
10answers
24k views

Help! My home PC has been infected by a virus! What do I do now?

This is an attempt to ask a canonical question as discussed in this old meta post. The goal is to create something helpful that can be used as a duplicate when non experts ask about virus infections. ...
161
votes
14answers
17k views

What is the safest way to deal with loads of incoming PDF files, some of which could potentially be malicious?

As an investigative journalist I receive each day dozens of messages, many of which contain PDF documents. But I'm worried about some of the potentially malicious consequences of blindly opening them ...
155
votes
5answers
21k views

How can USB sticks be dangerous?

We all know the story of the USB drive left outside a power plant which was found by a worker and inserted into a computer to see the contents which then allowed a hack to ensue. Here is my question, ...
155
votes
10answers
17k views

How do you explain the necessity of “nuke it from orbit” to management and users?

When a machine has been infected with malware, most of us here immediately identify the appropriate action as "nuke it from orbit" - i.e. wipe the system and start over. Unfortunately, this is often ...
154
votes
9answers
130k views

How secure are virtual machines really? False sense of security?

I was reading this CompTIA Security+ SYO-201 book, and the author David Prowse claims that: Whichever VM you select, the VM cannot cross the software boundaries set in place. For example, a virus ...
146
votes
20answers
38k views

Has it been mathematically proven that antivirus can't detect all viruses?

What analysis was Bruce Schneier referencing when he wrote: Viruses have no “cure.” It’s been mathematically proven that it is always possible to write a virus that any existing antivirus program ...
120
votes
11answers
37k views

Is there any way to safely examine the contents of a USB memory stick?

Suppose I found a USB memory stick lying around, and wanted to examine its contents in an attempt to locate its rightful owner. Considering that USB sticks might actually be something altogether more ...
109
votes
9answers
18k views

Alternatives to anti-virus for keeping oneself safe

I have read a lot of articles that talk about how using an AV is less safe than not having one for more intermediate PC users who are careful with what they click and download. For example, here are ...
90
votes
7answers
51k 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 desktop ...
87
votes
4answers
9k views

What is the risk of copy and pasting Linux commands from a website? How can some commands be invisible? [duplicate]

Like all beginners in the land of Linux, I usually look for websites that contain some useful shell commands, mark it with my mouse, copy it (CTRL + C) and paste it into a terminal. For example, if ...
86
votes
5answers
23k views

Can a malware power on a computer?

I've just downloaded and executed a piece of malware on my computer. I don't have much time right now, so I just powered it off (turned it off via the Start menu), hoping that it won't be able to ...
66
votes
3answers
16k views

What happens if you run WannaCry after installing the necessary patches?

I understand that WannaCry spreads itself by exploiting the SMBv1 vulnerability, which is fixed by patch MS17-010. Does this mean that even with the patch installed, WannaCry can still infect the ...
63
votes
4answers
60k views

Does a Virtual Machine stop malware from doing harm?

I would like to know if it is safe for the host system of a virtual machine (VM - VirtualBox OSE in my case) to execute malware. Can a virus break out and read or write data from the host system? ...
61
votes
5answers
17k views

Can Beehive detect a Snowden-like actor?

In a seminar, one of the Authors of Beehive: Large-Scale Log Analysis for Detecting Suspicious Activity in Enterprise Networks said that this system can prevent actions like Snowden did. From their ...
59
votes
7answers
7k views

Is it safe to install malware in a VM

Is it safe to install malware in virtual machines? I would like to investigate malware, but I don't want to infect my own computer. Can I install the malware in a VMWare VM, maybe even without ...
58
votes
4answers
5k views

What security risks are posed by software vendors deploying SSL Intercepting proxies on user desktops (e.g. Superfish)

There has been quite a bit of concern noted relating to the recent discovery that Lenovo are pre-installing a piece of Adware (Superfish) which has the capability of intercepting SSL traffic from ...
58
votes
2answers
6k views

Can you trace malware back to a specific keyboard?

A CNN article on the recent US Election hacks claims that ...the administration has traced the hack to the specific keyboards -- which featured Cyrillic characters -- that were used to construct ...
56
votes
11answers
30k views

Can headphones transmit malware?

Can headphones transmit malware? My friend borrowed my headphones (a pair of Apple EarPods) and plugged them into his Android mobile phone for a few minutes in order to listen to a voice message. ...
56
votes
9answers
17k views

How can empty USB sticks contain malware?

I read a BBC article about empty USB sticks containing malware: Berlin-based researchers Karsten Nohl and Jakob Lell said a device that appeared to be completely empty could still contain a virus....
52
votes
7answers
11k views

Why does one need a strong password on Unix?

SSH Server: I only allow public key authentication. Malicious Software: If it's running as my user it has access to my data and an internet connection, it's bad enough already. Yes, su access would ...
52
votes
4answers
177k views

Can a PDF file contain a virus?

Could a PDF file contain any type of malware?
48
votes
3answers
8k views

Can USB drive infect my PC with malware if I don't allow any autorun.inf to run?

Assuming that I'm using a trusted USB flash drive (meaning that it's not some device that looks like a USB drive and whose purpose is to damage my PC), is it possible for my PC to get infected from ...
46
votes
1answer
4k views

Can the previewable option in file managers execute malware?

I am using Nemo file manager and I enabled the Previewable files option that shows video/photo files with their thumbnails: I don't know exactly how files managers generate thumbnails, but I am ...
46
votes
4answers
105k 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 ...
45
votes
5answers
9k views

Does adding a password to BIOS prevent malware from infecting it?

I'm looking into ways of hardening a computer's security. One of the things is the BIOS. Does adding a password to the BIOS prevent malware from infecting it? I have seen this article: Protecting ...
45
votes
4answers
3k views

What cryptographic flaw was exploited by Flame, to get its code signed by Microsoft?

Today, Microsoft released a security advisory warning that the "Flame" malware exploited a weakness in a cryptographic algorithm used by Microsoft Terminal Server Licensing Service, and was thereby ...
44
votes
6answers
50k views

Is it dangerous to call spam phone numbers, even if you know they're spammers?

I sometimes like to check spam just to see how the messages look like, and I found someone who actually put an American phone number (1-XXX-XXX-XXXX). Most of these spammers are either trying to get ...
44
votes
3answers
3k views

Mars Curiosity Rover Security

Does the software in the Mars Curiosity Rover have any security features built-in? I can't imagine how someone would hack into it, but if the rover does indeed have some protection against malicious ...
43
votes
8answers
43k views

Is making a clean install enough to remove potential malware?

Is formatting the disk and reinstalling the system from scratch (to Ubuntu) enough to remove any potential hidden software spyware, keyloggers etc.? Or can something still persist installed in the ...
42
votes
5answers
11k views

Accidentally came across the source code for some malware, what to do?

I accidentally, the other day, went to a dodgy site, and today I discovered that in my cache there lay a text file. And after reading the contents of the file, I have deduced that it is the source ...
42
votes
2answers
14k views

How secure is the Windows 8 included Anti Virus known as Windows Defender?

How secure is the new Windows 8 anti virus known as Windows Defender? Does it have a protection against malware which uses UAC bypass/process injection/rootkits/process persistence/running the binary ...
42
votes
3answers
93k views

Can you get virus just by visiting a website in Chrome?

I've recently read Google Chrome: The End of Drive-By Downloads. Is it true to say that drive-by-downloads are history in Google Chrome? So if I have a link (from a spam email) I can right-click >> ...
42
votes
6answers
11k views

How do I safely inspect a potentially malicious website?

Sometimes I'm interested in what's behind a malicious website. How do I stay on the safe side if I decide to inspect? I'm searching for methods that are quicker and more simple than running the ...
42
votes
3answers
7k views

How to detect if I am vulnerable to “Superfish,” and how to remove it?

The site has already a discussion of the security risks of "Superfish". It seems to me that anything that tampers with the bits of one's connection is bad. If it tampers with TLS connections, it is ...
40
votes
7answers
19k views

Can cookies carry viruses?

I was wondering whether a cookie can carry a virus (or any security-threatening code). In some sense it is similar to a download. So by simply visiting a site, could I get harmed?
40
votes
5answers
6k views

Are there actions taken against websites that deliver malware?

There are serious tools and services such as Google Safe Browsing for malicious and phishing websites, and others fully dedicated to phishing websites such as Phishing.org. What is done against these ...
40
votes
4answers
6k views

Have computer criminals been known to exploit easily-edited websites like Wikipedia to embed malicious scripts?

When I was reading a page on Wikipedia several months ago (December 2014) I saw what looked like a pop-up window from BT, but I soon realized that when I closed the page the pop-up disappeared. I then ...
40
votes
5answers
5k views

How should source code security be checked?

How to check whether the source code of an open-source project contains no malicious content? For example, in a set of source code files with altogether 30,000 lines, there might be 1-2 lines ...
38
votes
5answers
46k views

Is HTML5 vibrate feature a security vulnerability?

While surfing a news website on my mobile, I receive a virus infection alert warning that triggers my phone to vibrate incessantly. The alert looks like the following: I didn't expect my phone to ...
37
votes
6answers
10k views

Can malware be dangerous even when quarantined?

I am reading a book on network security and when talking about user confusion it writes: "It is not uncommon for a user to be asked security questions such as Is it safe to quarantine this ...
37
votes
5answers
4k views

Risk of tampering when hardware shipment is delayed

I am currently receiving an order of computer parts in the mail including an SSD. Tracking showed that the package arrived in my town on day X, and was originally scheduled for delivery on day X as ...
37
votes
12answers
38k views

How to safely view a malicious PDF?

I have a PDF with important information that may contain malware. What would be the best way to view it?
34
votes
6answers
42k views

How do I safely inspect a suspicious email attachment?

I received a pretty blatantly spammy email to my Gmail account. I'm not really sure how it made it through the spam filters, since it has all of the telltale signs. The FROM field is spoofed as ...
33
votes
5answers
2k views

Why would malware try to remove other malware?

Recently my php-based website got infected with malware (probably by a stolen ftp password). Basically, every 30 minutes a file frame_cleaner_php.php was uploaded, a HTTP-GET was done on it to execute ...
33
votes
8answers
43k views

How is it possible to embed executable code in an image

I was reading up on FireEye and came across this NYTimes article detailing a Skype chat where an image was sent laden with malware: Quote: To gain access to information on the devices..., hackers ...
33
votes
4answers
4k 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 ...
32
votes
4answers
5k views

Why does malware periodically check google.com

I'm looking at some malware PCAPs, e.g. http://malware-traffic-analysis.net/2014/05/27/index.html . One of the things I've been seeing frequently is requests to alexa top million sites (e.g. yandex, ...