The operating system is the software component that provides abstraction of physical hardware, and provides a generalized model for application software to execute without the need for specific hardware knowledge. Questions on the topic of operating system security should use this tag; you may also ...

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Where and how do operating systems save passwords for user accounts?

Where do operating systems (e.g. Windows) save their passwords? Do they store them in plain text? Do they use hardware modules such as TPM? Are these methods generally considered secure?
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How can I recover encrypted files after system reinstallation

I had a file which contains images and videos, I was using the windows 7 ultimate and I had encrypted the file. Now I have copied that file to my hard disk and format that operating system and again. ...
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Can viruses actually inject their code in other processes?

Can a virus really inject its own code into a process so it stays on your computer permantly? The only way to actually remove it is to reinstall your OS. My question is how can it do that without ...
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1answer
703 views

Are there Linux rootkits circulating that directly modify the kernel (without modules)?

It has been said, over and over, that disabling dynamic kernel module loading on Linux increases security. I understand why people give this advice, but I've always assumed that a bad guy could ...
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8answers
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Battling Malware without spending money

Our environment consists of about 80 users running Windows 7. Previous to me showing up as a full time IT employee, the company had contracted an outsource IT solution. As part of their set up, they ...
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3answers
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Security of passwords remembered by Windows

Does Windows XP or Windows 7 encrypt saved passwords? I'm assuming that the user uses local password to logon. The user then uses his own computer to connect to server in work and sets the "remember ...
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Is there any asymmetrically encrypted file system?

Is there a file system providing a directory where everybody can write, but only the directory owner can read the files? In theory it could be done by encrypting using the public key while writing, ...
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2answers
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Running proprietary software on Linux safely

As a summer project, I'm looking to prevent any piece of proprietary software like many games I run from have access to my personal files. After looking a lot at sandboxing, I've decided that anything ...
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5answers
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How can I protect my computer from my potentially malicious colleagues?

So, I work in this small company (10 people) where we do stuff in programming, for various platforms. I started recently working there (2 months) right after I graduated. My work is not exactly ...
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2answers
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Security logs on Linux, Solaris and Windows

As the company's security department, our system administrators ask us what they need to log for SIEM (Security Incident and Event Management). We don't have any prepared documents and are seeking ...
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What are the security implications of enabling WINRM on all domain members?

As Powershell becomes more and more popular, it appears that using WINRM may end up being a better option than using PSEXEC from SysInternals for remote management. Given that WINRM is disabled by ...
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5answers
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Browsing on a USB OS (Linux) safe from malware?

Let's say I have a computer. It's a personal computer - the one you'd typically find in homes. In this scenario, it's running Windows XP SP3, although it could run 7, Vista, etc. I have a USB drive ...
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3answers
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Remote return into libc attack

It is often shown that non-executable data segemnts are possible to bypass through return-to-libc attacks. It's evident on /bin/sh but is it also possible to invoke a remote shell?
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Security Risks Involved in Deploying Win Server 2008 on a Linux host

The Question: Are there any major security risks I should be concerned about, caused by installing Windows Server 2008 R2 onto a Linux Host in VirtualBox? I run an Ubuntu box, with a fully-secured ...
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1answer
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How can one gain additional privileges from being able to read kernel memory?

Given the ability to read (but not write) arbitrary kernel memory as an unprivileged user, what approaches might one take to gain additional privileges on the system? Ignoring the 'trivial' method of ...
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3answers
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Is it safe to attach a potentially malicious hard drive to a Solaris machine?

We bring in hard drives from un-trusted sources and would like to ensure that they will not contain any harmful content. What kind of risk is there for Solaris? As in, if Solaris is running, and I ...
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2answers
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Sun ILOM / Out of band management security concerns

I would like to get some outside opinion on this if possible, although I do not know what to ask. Sun ILOM is an Out-of-band management system. I understand it is a separate OS on the box that is ...
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4answers
314 views

Data categorization: Critical or not

I need to provide two means for securing data within my application. First is using the Operating System sandboxing model (I am talking about Mobile Phones OS) and the second using the OpenSSL AES ...
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4answers
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How does System Memory Dump work?

So there are so many pen-testing tools that perform a memory dump on the system. How exactly do they work - what exactly happens ?
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6answers
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What is preventing the widespread common use of MAC-type systems?

Overall question what is preventing the uptake of MAC systems such as SELinux/AppArmor in corporate and desktop computing environments? Why don't you think it isn't already widespread? I do not ...
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2answers
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Can Windows malware harm a Linux computer when it's executed with Wine?

I am an (Ubuntu) Linux user. Sometimes, I have to use Wine for running Windows executables. I would like to know if Windows malware (virus, trojan, worm,...), i.e. malware that was not intended to ...
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3answers
646 views

SCADA Operating System & Security Exploits

So I have a basic question on the SCADA operating system, which the manufacturers do not disclose. From my experience I can see VxWorks running in some of them, and Windows or Linux in some of them. ...
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3answers
427 views

Virtualization as a layer of security for desktop computers?

Given the amount of 3rd party plugins required to browse the web, I've been compelled to virtualize my online habits to gain an additional layer of security. There is of course some obvious ...
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5answers
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Linux command logging?

Recently someone broke into one of our linux servers as a non root user. An excerpt from .bash_history: [...] perl perl set +o history set +o history set +o history passwd sdfsdf passwd exit I ...
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2answers
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Digital Forensics and Pentesting: what now?

So, i want to enter the security field, and i'm leaning towards security auditing, digital forensics, and reverse engineering. i'm in school right now, i'm studying x86 ASM, exploring Linux, and soon ...
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1answer
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Windows task manager can see all processes as non administrator without permission

On Windows Server 2008 R2 operating as a standard user, when I open Task Manager I can see all the processes from different users on the system. I have the option to click "Show all processes" which ...
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How to manually check for rootkits on a server

Does anyone have a general step by step list on how to try discover rootkits on a Linux or Solaris server? I'm looking for to to manually find the rootkit, not by automated software. For example: ...
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1answer
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Firefox Desktop Shortcut Being Renamed

On my Vista PC the Firefox shortcut icon is being randomly renamed. The name changes to some variation of a recently visited URL. This unwanted action has survived several version updates. Of course I ...
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3answers
955 views

Attacks against windows kiosk software

I am interested in potential/actual attacks against kiosk software. I am not talking about physical access, or specifically designed kiosk operating systems or shells, bur rather software that runs ...
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6answers
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Why shouldn't I run other applications on a Firewall?

If I want to use Ubuntu 11.04 as a Firewall in SOHO environment, then I just can't figure out what is the bad thing about installing GUI on it (e.g.: XFCE)? The only opened port to the world (wan ...
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1answer
287 views

Attacks against HIDS software running on the same machine

I am interested in the attacks that could be used to compromise or disable HIDS software such as Tripwire or Samhain. I understand that ideally checks should be run periodically and the database ...
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5answers
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Secure mount options + partitioning on Ubuntu

What is the best solution for mount options/partitioning when having e.g.: an Ubuntu minimal install (11.04) for Desktop use? e.g.: put /tmp on different partition to give it mount options like: ...
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5answers
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Where to download OpenBSD release ISO's over HTTPS?

OpenBSD claims to be highly secure. So why doesn't it allow downloading the release iso's over HTTPS? Or I'm missing something? Can someone please explain this to me?
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2answers
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Recommend Keylogger for Ubuntu?

I purchased a new laptop recently, and I'm working on hardening it. Specifically, I'm interested in increasing my chances of recovering the machine in the event that it's ever stolen. The system ...
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6answers
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Secure Linux Desktop

I'm looking for hints about secure linux desktops. Securing servers is no problem. Most recent Software Updates, run only the services required etc. But what about desktops? I'm thinking about details ...
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4answers
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How to disable Firewire in OpenBSD/Linux to prevent attacks through Firewire?

Since Firewire lacks security, allowing a plugged-in device to access host memory, it's a good thing to fully disable it. If we're not using the BIOS to disable the Firewire port then how could we do ...
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2answers
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OSes that are mathematically proven to be 100% (or 99%) secure?

Are there any? What are their names? Are they publicly available/downloadable/installable?
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3answers
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OS Kernel Hashing

Has anyone had experience with or is aware of any products that hash the OS kernel? This would be used, ideally, for watching for system compromises, auditing, change management, etc. I am looking ...
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1answer
783 views

Does Fedora 15 still use suid bits?

I heard that Fedora 15 will not use suid bits. Is that true? Is the suid bit a security design bug?
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3answers
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What differences are there between built-in Administrator and other Administrators?

Are there any significant differences in the rights, privileges, permissions, or other powers held by the built-in Administrator account, and those held by non-built-in Administrator accounts?
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1answer
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Does sandboxie “grab” all the system calls?

Sandboxie: http://www.sandboxie.com Does sandboxie "grab" all the system calls, e.g.: filesystem calls? Or it "grabs" all the low level calls from a process?
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How does the Windows “Secure Desktop” mode work?

Can anyone explain (or provide a link to a simple explanation) of what the Windows "Secure Desktop" mode is and how it works? I just heard about it in the KeePass documentation (KeePass - Enter ...
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1answer
191 views

OBSD X11 as non-root?

If running X11 as root is not a very good idea, then can anyone mention a method/solution, how to still use a GUI, and not having X11 as root?
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1answer
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OpenBSD-based LiveCD/LiveDVD - is it secure? is it offical?

Does the OpenBSD LiveCD/LiveDVD get deeply audited like the original OpenBSD? Is it an official "port"? Experiences with it?
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3answers
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Is CentOS a good choice from a security perspective?

How secure is the CentOS Linux distribution? I noticed there were times when there were no up-to-date patches for some version of CentOS (e.g., 5.6). I read this on some mailing list that I can't ...
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3answers
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Are passwords in memory?

I have an encrypted HDD (dm_crypt). That's why I store my passwords in a simple text file. I usually copy/paste the passwords from it. Ok! Q: If I open this text file then it goes into the memory. So ...
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2answers
262 views

Patching Mechanism and security holes

Let me clarify two methods of patching softwares and then I will go straight to the question: I am using both MAC OS X and Windows and different mechanisms of these two famous operating systems in ...
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2answers
277 views

How can I detect users that have requested AD Administrators to reuse an expired password?

There is a trend among companies I've worked at where administrators (or helpdesk folks) give a user a courtesy extension of the old expired password... rather than forcing the user to change it. ...
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1answer
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Security Risk of Disabling forceguest in non-AD Environment

Our application group is looking to deploy a product which requires that we disable forceguest in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa. We are running on a Novell network (I know, I ...
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Practical non-government uses of Biba, Bell-LaPadula, etc. models

For example, the Biba model is now hanging out in current versions of Windows. Things downloaded from the Internet are tagged as such. Internet (low) stuff can't alter user (medium) stuff which isn't ...