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272 votes

Search for military installed backdoors on laptop

If the device left your sight for any amount of time, replace it. It can no longer be trusted. The cost to assure it can still be trusted significantly exceeds the cost of getting a new one There is ...
forest's user avatar
  • 67k
214 votes

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

Under one possible interpretation of that, it's a result of Rice's theorem. A program is malicious if it performs some malicious action, which makes it a semantic property. Some programs are malicious ...
Joseph Sible-Reinstate Monica's user avatar
194 votes

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

Actually, the opposite can be easily proved: since all computer viruses are executable code in one way or another, all you have to do is write an antivirus program that will report ANY executable code ...
walen's user avatar
  • 1,777
178 votes

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

What do I do now? How do I get rid of the virus? The best option is what is referred to as "nuke it from orbit." The reference is from Aliens: The idea behind this is that you wipe your ...
CaffeineAddiction's user avatar
162 votes

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

I think the safest option for you would be to use Qubes OS with its built in DisposableVMs functionality, and its “Convert to Trusted PDF” tool. What is Qubes OS? Qubes is an operating system where ...
142 votes

Can Beehive detect a Snowden-like actor?

A backup operator will have the permission and behavioral markers of someone that moves lots of data around. Like any sysadmin where there's no dedicated backup operator in place. Snowden was a ...
ThoriumBR's user avatar
  • 54.6k
140 votes

How to investigate an unknown 1.5GB file named "sudo" in my Linux home directory?

You probably made it by accident with a botched shell command. I've done stuff like that myself. As a result it is probably filled with innocuous data. Here are a few reasons why I would guess it is ...
Conor Mancone's user avatar
136 votes

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

WannaCry attacks are initiated using an SMBv1 remote code execution vulnerability in Microsoft Windows OS. The EternalBlue exploit has been patched by Microsoft on March 14 and made publicly available ...
Nik Nik's user avatar
  • 1,292
133 votes

If malware does not run in a VM why not make everything a VM?

One has to take into account why the malware is doing this distinction in the first place. Some malware does not run in the VM because the chance is high that this VM is used for inspecting the ...
Steffen Ullrich's user avatar
131 votes

Alternatives to anti-virus for keeping oneself safe

Antivirus is more dangerous in that it parses complex attacker-controlled data in a highly privileged context. This is a recipe for privilege escalation exploits. As a result, sophisticated attackers ...
forest's user avatar
  • 67k
127 votes

Can a malware power on a computer?

TL;DR Yes, but it's unlikely. Just to be sure, either unplug the PC or ensure it can't connect to anything. Several operating systems - notably Windows 10 - have the possibility of setting "...
LSerni's user avatar
  • 22.9k
123 votes

Can a virus destroy the BIOS of a modern computer?

Modern computers don't have a BIOS, they have a UEFI. Updating the UEFI firmware from the running operating system is a standard procedure, so any malware which manages to get executed on the ...
Philipp's user avatar
  • 49.4k
100 votes

Can malicious code fit in 14 bytes?

Yes, it can. It could be just the trigger vulnerability which would load data on specific areas of the movie in memory and execute. The malicious part can be pretty small, and the payload could be ...
ThoriumBR's user avatar
  • 54.6k
97 votes

My email address is being used to enroll for online services. Should I be concerned?

Should I be concerned about this? Yes. This should be of concern to you because an attacker was able to obtain the valid password for your Gmail account. From the details of warning you have ...
hax's user avatar
  • 3,941
95 votes

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

According to Wikipedia: In 1987, Fred Cohen published a demonstration that there is no algorithm that can perfectly detect all possible viruses. It also references this paper. That might be the ...
Harry Johnston's user avatar
93 votes

Can cookies carry viruses?

You can put any text strings into a cookie, so in theory you could put some kind of code there. But for code to do any harm something needs to run it. The web browser does not interpret the content of ...
Anders's user avatar
  • 65.7k
93 votes

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

If you download and execute WannaCry, it will still lock your files and attempt to infect other unpatched computers in the network. WannaCry only needs the SMB exploit to get into a system, not to ...
knbk's user avatar
  • 751
85 votes

Can headphones transmit malware?

I doubt there is a way to store any information (thus transfer information) on regular headphones. Some more advanced models (such as noise canceling) have some processing ability and firmware, but I ...
Stephen Spencer's user avatar
85 votes

Does open source "protestware" represent a security risk?

Political statements in software can be a concern for a few reasons: The may result in the software being banned in your country, so you should plan for that eventuality. They may result in the ...
Gh0stFish's user avatar
  • 13k
84 votes

Would a CD drive on a driverless car pose a security risk?

Not on a well-designed car The CD player is part of the media system. It's likely that the media system has a number of security vulnerabilities, and a malicious CD can probably take control of the ...
paj28's user avatar
  • 33.8k
75 votes

Was actually crazy malware in 2006?

Let me summarise what you are seeing: someone navigates to a typo-squat site ( the browser is then flooded with numerous pop-ups, warning windows, etc. eventually, the anti-virus starts to ...
schroeder's user avatar
  • 131k
74 votes

Search for military installed backdoors on laptop

The main information we are lacking is your threat model. Is it likely that the military targets you specifically, and would be willing to expend some resources on you? We don't need to know the ...
Tom's user avatar
  • 10.6k
73 votes

Can the previewable option in file managers execute malware?

Yes, it is possible for previews to execute malicious code. Previews are created by checking the file type, and generating a thumbnail. For images, it resizes them. For videos, it decodes them, seeks ...
forest's user avatar
  • 67k
69 votes

How can empty USB sticks contain malware?

I'm afraid this stems from a misunderstanding from the reporter: ... said a device that appeared to be empty could still contain a virus. In the video the reporter's referring to it is clear, in ...
autistic's user avatar
  • 759
66 votes

Should one buy new hardware after a system compromise?

You must do risk management. How likely it is that you and your laptop have been personally targeted? The vast majority of persistent malware operates entirely in software, and formatting the disk is ...
forest's user avatar
  • 67k
65 votes

Can a malware power on a computer?

As others have mentioned, it is quite possible on most PC hardware, although currently not very likely (as vast majority of malware does not bother). What others have said is not possible is however ...
Matija Nalis's user avatar
  • 2,305
64 votes

Can you trace malware back to a specific keyboard?

A keyboard is not a typewriter. Keyboards produce scancodes that are interpreted by the software and mapped depending on your layout. When a key press produces a letter on your screen it's nothing ...
Arminius's user avatar
  • 44.9k
63 votes

Why does one need a strong password on Unix?

You seem to have a pretty clear understanding of the risks. As others have stated it highly encouraged to use a strong password, so if you are running a sensitive service, then by all means, please ...
700 Software's user avatar
63 votes

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

The ransomware is using a known, publicly disclosed exploit in SMBv1 (Server Message Block Version 1). It is an application level protocol used for sharing files and printers in a networked ...
dark_st3alth's user avatar
  • 3,032

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