235
votes
Accepted
How are anti viruses so fast?
Disclosure: I work for an anti-virus vendor.
Because most anti-virus engines were born as protecting endpoints, and even now for many of them endpoint protection is major part of business, the modern ...
- 3,544
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 ...
200
votes
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Company claims hardwire connections are a security issue
Warning: Conjecture, because none of us know their actual setup.
It is very likely that the organization has their own network, which is hard-wired, as well as a guest network, which is wireless-only....
- 73.2k
195
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 ...
- 1,787
178
votes
Accepted
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 ...
- 7,922
162
votes
Accepted
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 ...
131
votes
Accepted
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 ...
- 67.1k
100
votes
Accepted
Replacing Windows 7 security updates with anti-virus?
Nope.
After Microsoft discontinue security updates for a version of Windows there is not a safe way to run that version of Windows.
Some people will promote Virtual Patching where you have a ...
- 2,811
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 ...
- 1,667
66
votes
Can anti-virus/virus protection be used to spy on you?
Any software you install on your system can compromise the system and thus affect security and privacy. This can be done either willingly or because of bugs in the software. And this is doubly true ...
- 206k
52
votes
How are anti viruses so fast?
The common anti-virus (to my knowledge) use a kinda brute force type method where they get the hash of the file and compare it to thousands of known virus' hash. Is it just they have servers with ...
- 22.9k
45
votes
Are there any known cases of antivirus software intentionally sending false alarms?
I have not seen false alarms, but I have seen an excessive amount of warnings/notifications, with Avast, for example. You could receive warnings about how vulnerable you 'might' be, and how you could ...
- 1,595
38
votes
Replacing Windows 7 security updates with anti-virus?
No, anti-malware is not a replacement for security updates.
Neil Matz summarized the Fortinet's Q2 Global Threat Landscape report for 2017, noticing:
WannaCry and NotPetya targeted a vulnerability ...
- 19.2k
37
votes
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Norton detects intrusion attempt from virtual machine - how is this possible?
You are assuming that the intrusion is coming from the VM to the hypervisor. A VM "breakout" is when the VM accesses the host directly.
An infected VM that has access to the network can ...
- 132k
35
votes
Accepted
Are there any known cases of antivirus software intentionally sending false alarms?
The problem with deliberately triggering false alarms is that users will at some point lose trust in the AV software. The rates of false positives are also an important factor in AV rankings - and ...
- 45k
32
votes
Help! My home PC has been infected by a virus! What do I do now?
I'm sorry to hear you've got a computer virus. Fortunately, thousands of people deal with virus infections daily, and in most cases, the computer and all data can be restored. By following good online ...
- 34.6k
30
votes
Can a virus infection spread from a PC to a PCB and back to a PC?
It's impractical for a PCB to be a vector for malware storage or attacks, but that's because PCBs don't do anything except route electrical signals between components. The components themselves... ...
- 50.3k
29
votes
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Do Linux systems need antivirus against ransomware?
There are actually multiple parts of the question:
Is Linux affected by malware and especially ransomware?
Do antivirus products exist for Linux?
Do these products help against this threat?
To ...
- 206k
29
votes
Accepted
Is it acceptable to exclude folders in antivirus?
Ah yes, ye olde problem of security tools making a system unusable. My arch nemesis.
when is it acceptable to exclude folders in antivirus, and why?
Short answer:
There's an old adage on this site ...
- 59.2k
29
votes
Zero-day prevention. Is there a Windows program that encrypts files on-the-fly, keeping only the currently open file decrypted?
First things first: Asking for software recommendations is off topic for this site and you should instead use the Software Recommendations site. I'm going to mostly talk about why what you're asking ...
- 50.3k
28
votes
Company claims hardwire connections are a security issue
It really depends on how they have set up their network, so we can only speculate. But I can provide a similar anecdote.
My local library has a wifi that you can log into using your library card. ...
- 59.2k
26
votes
Has it been mathematically proven that antivirus can't detect all viruses?
The statement can't be mathematically proved unless it is reformulated as a mathematical proposition.
At the very least, that requires a mathematically sound definition of what a "virus" is: which is ...
- 491
25
votes
Help! My home PC has been infected by a virus! What do I do now?
Honestly, "non-technical users" are typically unaware of the basic conceptual difference between a data "file" and an "application", nevermind the minefield of subtleties in the advanced war game ...
- 696
24
votes
Can a virus infection spread from a PC to a PCB and back to a PC?
That depends on the specifics of your PCBs, but in the absence of more information, I would follow your IT security team: they know more about them than us on this Q&A website.
It is in theory ...
- 10.6k
19
votes
Alternatives to anti-virus for keeping oneself safe
This is more opinion than fact, but the answer is a definite "Maybe!"
Let's narrow our scope to Windows for a moment, since it's the biggest Anti-Virus market around.
Windows Defender (the default ...
- 3,721
19
votes
Has it been mathematically proven that antivirus can't detect all viruses?
tl;dr- The answer depends on exactly what requirements you impose on the question.
If you merely want to detect all viruses without further constraint, then simply flag anything and everything as a ...
- 1,451
19
votes
What is the best way to protect from polymorphic viruses?
As the quote points out, polymorphic malware exploits the limitations of signature-based malware detection. To deal with this, it's common to also use behavior-based detection, i.e., heuristics which ...
- 17.7k
18
votes
What is the safest way to deal with loads of incoming PDF files, some of which could potentially be malicious?
Safest would probably be a burner device. Grab a cheap laptop, and a mobile internet dongle, use it to download the documents, and manually copy across any contents to your main computer (literally ...
- 27.4k
18
votes
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How to remove quarantined virus securely?
Although a lot depends on the anti-virus software, I'll try to answer your questions:
1) What is the best practice and secure way to deal with them? Delete from quarantine, or let them in there?
...
- 4,444
17
votes
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How AV software makes sure quarantined files never get executed?
There are a couple ways an antivirus program might go about preventing the execution of a quarantined file:
Hold it open for exclusive access. It can simply use the normal CreateFile API and pass ...
- 2,501
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