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238 votes
Accepted

Why is the OS obfuscation defense against "It's a Unix system!" not widely implemented?

Before I tear your idea apart, let me say that it's a really interesting idea and it was super fun to think about. Please continue to think outside the box and ask interesting questions! Alright, let'...
Mike Ounsworth's user avatar
154 votes

Can you hide your OS from programs? Can you trick a program into thinking you are on a different OS?

Cheeky answer: I think you are about to invent a Virtual Machine. In order to spoof the hardware to look like a 2003 motherboard you'll need to deal with things like writing a CPU instruction ...
Mike Ounsworth's user avatar
123 votes
Accepted

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
91 votes

Why is the OS obfuscation defense against "It's a Unix system!" not widely implemented?

Mike's answer says basically everything I have to offer about why this is a bad idea from a development perspective (and, as Ghedipunk's comment says, an unusable security feature provides no security)...
CBHacking's user avatar
  • 49.6k
79 votes
Accepted

Is an up-to-date browser secure on an out-of-date OS?

Do not use an outdated OS, even with a modern browser. Assuming that after that day I still use an updated browser, is it true that I'm still safe? No, you cannot avoid browser-based security ...
forest's user avatar
  • 67k
72 votes
Accepted

What is protection ring -1?

The "rings" nomenclature (0-3) you usually see these days started with the requested privilege level field in segment selectors as part of the design of x86 protected mode. Back in the day, it was ...
diagprov's user avatar
  • 2,094
66 votes
Accepted

Can you create a fake (malicious) Ubuntu iso

If an OS is open source or not is not the important factor if someone could build a malicious installer image. Recent versions of Windows use a technique that bases on WIM images which can be ...
Robert's user avatar
  • 1,461
61 votes
Accepted

Why is there a need to modify system call tables in Linux?

You can check if they are read-only by looking up the kernel symbols. The "R" means read-only.* $ grep sys_call_table /proc/kallsyms 0000000000000000 R sys_call_table 0000000000000000 R ...
forest's user avatar
  • 67k
55 votes

Would it be more secure or not if all computers in the network use the same operating system?

In 2003, Dan Geer from @Stake published a seminal paper on this very topic - CyberInsecurity: The Cost of Monopoly. Surprisingly (given that he was employed by Microsoft at the time) he comes ...
gowenfawr's user avatar
  • 73k
48 votes
Accepted

Are there any OSes that verify program signatures before executing them?

iOS and Android both validates the signature of every single piece of code before loading them into memory. Windows UWP apps are also all checked for signature before being loaded as well. Package ...
Stephane's user avatar
  • 18.7k
48 votes

Can a virus destroy the BIOS of a modern computer?

Yes, it is definitely possible. Nowadays, with UEFI becoming widespread, it is even more of a concern: UEFI has a much larger attack surface than traditional BIOS and a (potential) flaw in UEFI ...
Stephane's user avatar
  • 18.7k
46 votes
Accepted

What are the risks of desktop personalization on Windows?

Changing them to other Windows defaults would pose no security risk. Allowing people to install fonts or screensavers from third parties poses a HUGE security risk. However, it's most likely these ...
CaffeineAddiction's user avatar
32 votes

Would it be more secure or not if all computers in the network use the same operating system?

If all the systems are the same, then there is predictability of what could go wrong and how to fix and patch. It becomes a lot easier to mitigate problems that you know about. For instance, if the ...
schroeder's user avatar
  • 131k
31 votes

Can you create a fake (malicious) Ubuntu iso

First of all: This would require a faked checksum as well, but that is somewhat besides the point because it can be faked too. What do you mean by faked? If the user checks the checksum against the ...
user9123's user avatar
  • 583
30 votes

Why is the OS obfuscation defense against "It's a Unix system!" not widely implemented?

If your objective is to deprive an attacker of ls and cat, there's an even better alternative to obfuscation: just don't install those utilities. While I wouldn't say this is a widely implement ...
Phil Frost's user avatar
30 votes

What is the frequency of open security bugs in an operating system with increasing age?

Interesting theory but... Even in open-source code, serious bugs can go unnoticed for a very long time (think Log4j), because nobody had the time or inclination to analyze the code. Probably, a three-...
Kate's user avatar
  • 8,435
28 votes

Are there any OSes that verify program signatures before executing them?

Why do not all OS verify signature of programs? Simply because in the early times, most programs were written and compiled locally, and still nowadays, some business applications are specifically ...
Serge Ballesta's user avatar
27 votes
Accepted

Should I worry about compromised firmware when reinstalling an OS?

Basically yes, you're right to worry. However, it's not the garden variety adversary that has that kind of capabilities... Also more and more update mechanisms are protected by a signature check, and —...
Bruno Rohée's user avatar
  • 5,507
26 votes
Accepted

How do I hide the OS I am using from internet sites?

It is not currently possible to hide the type of OS from a website A solution against general fingerprinting and obtaining more specific information about your system is to use Tor Browser with the ...
user163629's user avatar
25 votes

Can you hide your OS from programs? Can you trick a program into thinking you are on a different OS?

Depending on the level of "trick" you want, you might be able to do this with built-in compatibility features. Windows supports running programs in special modes that emulate older versions and/or ...
CBHacking's user avatar
  • 49.6k
24 votes
Accepted

Is Qubes OS more secure than running a set of activity related VMs?

Joanna Rutkowska, leader of the Qubes project, does a great job into documenting the concepts on which Qubes is relying. I therefore strongly suggest you to get the information at the source, and in ...
WhiteWinterWolf's user avatar
23 votes

Why is there a need to modify system call tables in Linux?

As noted by forest, modern Linux does not allow this, but it's easy to override. However, historically it was useful (and maybe still is) for security purposes: hot-patching against vulnerabilities. ...
R.. GitHub STOP HELPING ICE's user avatar
22 votes

What are the risks of desktop personalization on Windows?

Sometimes blocking desktop personalisation can be a HR issue rather than a security one. For example, if you allow people to set their own backgrounds, sooner or later someone is going to set ...
Gh0stFish's user avatar
  • 13k
21 votes
Accepted

What are the criteria to choose a secure operating system?

There are many criteria you can use for choosing a secure operating system. This includes everything from the features explicitly supported to the overall goal of the system itself. Although this ...
forest's user avatar
  • 67k
21 votes

Can a virus destroy the BIOS of a modern computer?

Practically speaking, a virus is software, so can do anything that any other software can do. So the simple way answer to this question, and all others of the class "Can viruses do X?" is to ask "...
Dewi Morgan's user avatar
  • 1,439
19 votes

How can Linux be secure if it allows for open source contributions from the public?

You are misunderstanding how open source software development works. Not just anyone can modify the kernel, so no "unknown developers from around the world" are submitting mysterious lines ...
forest's user avatar
  • 67k
13 votes

How could one say that older operating systems are more vulnerable?

You need to make one adjustment to your conclusion: So, I see Windows 10 gets more infected than Windows 98 Should be So, I see Windows 10 gets more infected than Windows 98 by the programs I ...
schroeder's user avatar
  • 131k
13 votes
Accepted

How could one say that older operating systems are more vulnerable?

There is one flaw in your premise that since those malware ran on windows 10 but not on 98 and hence windows 98 is safe. By that logic, I can say that my shell script cleared the contents of a linux ...
Limit's user avatar
  • 3,276
13 votes

Is penetration testing becoming objectively "harder" as apps/protocols/operating systems become more secure?

The objective of penetration testing is not to find vulnerabilities, and so it hasn't failed if it doesn't find any. It's to check whether or not vulnerabilities are present. It doesn't get harder if ...
Mike Scott's user avatar
  • 10.3k
13 votes

Would it be more secure or not if all computers in the network use the same operating system?

More diverse systems make it more difficult for an infection to spread.* Less diverse systems make it more difficult for an infection to start.** So if your failure scenario is all your systems ...
Peter's user avatar
  • 3,630

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