Category: Other

Other computing tips

Capture DNS queries with DNSQuery Sniffer

DNSQuery Sniffer is a free Windows application that captures your computer DNS queries, the program is useful to troubleshoot name resolution complications and check if a domain name is being blacklisted by your ISP DNS. There is no need to install the program, you can run it in portable mode and carry it with you on a USB thumbdrive.

When you run DNSQuery Sniffer for the first time you will shown the available network adapters in your computer, including virtual host components presented as a separate network cards. Your initial choice of capture options will be set as default, to change them later on you will have to access Options>Capture Options or click F9, there are shortcuts to access many of the functions.

DNSQuery Sniffer capturing DNS queries

I recorded my DNS queries while on a VPN and it worked perfectly well. A VPN encrypts data in transit over the Internet but recording takes place before DNS queries leave the router. Another use for this program could be for a system administrator to spy on network users, if you are using a portable VPN on an Internet Cafe, DNSQuery Sniffer is one of the many tools a computer admin can deploy to monitor in real time at what sites you are visiting.

Some of the details recorded include Host name and port (for example: pagead2.googlesyndication.com:54630), DNS query time stamp, request time and response time, reverse DNS lookup, IPv6 server address, destination IP address and many others. I noticed that most of the requests only show hostname and port, itemised displayed details will depend on what server you visit.

While I was recording outbound queries on my computer I was able to see Google Adsense and Facebook queries created by the plugins embedded in the website I just visited. Logs can become huge within a couple of recording hours, they can be exported as CSV/XML or HTML file and import them into a spreadsheet for processing.

This tool will be useful for system administrators. Home users without logging needs might prefer to troubleshoot DNS problems with another freeware called DNS Benchmark.

Visit DNSQuery Sniffer homepage

19 June, 2013
Firefox addon warns you of NSA PRISM surveillance

Dark Side Of The Prism is a Firefox addon that will show a dark PRISM logo on your screen every time you visit a website that is known to allow gathering of user’s data to the US National Security Agency. The addon will work on a company’s main website and all of its associated services.

For example, the Bing search engine is included in the list of PRISM websites along with all other Microsoft owned websites because Microsoft was named in the leaked NSA documents listing partner companies.

Dark Side Of Prism Firefox addon

This addon is a good way to remind yourself that you are being spied on at all times on the Internet and it will also play Pink Floyd’s aural prism “Dark Side Of The Moon” album while it shows the PRISM logo, different tracks will play on different sites. The looped music can get a little over your head as there is no way to mute it other than leaving the site, Dark Side of the Prism will force you to close the tab and go to an alternative company or you will get stuck with annoying music and a scary black logo.

The source code is available for review in case you are paranoid and suspect this addon could be another NSA invention to spy on people.

Visit Dark Side of The Prism addon

18 June, 2013
SSH in your browser with Chrome Secure Shell

Chrome Secure Shell is a terminal emulator, you can use it to access a remote server from within your browser, it replaces PuTTY in Windows and ssh in Mac/Linux computers. Secure Shell can emulate most things any xterm Unix terminal can do. Secure Shell runs hterm, an HTML terminal emulator written in JavaScript, it does not provide SSH access on its own but it can connect to any server running sshd on any port and it will be as secure as ssh. Executed commands are sandboxed inside the browser, this stops malware from spreading to your computer.

Combined with a shell account the Secure Shell Chrome extension could be used to bypass Internet filtering. With sparse Linux command line knowledge it is possible to launch the Lynx browser in the remote server and access filtered websites, or use the Alpine email client or irssi IRC client within the shell.

Chrome Secure Shell SSH

SSH server login might be accomplished with the traditional username and password or the much more secure digital certificate authentication system, this makes credentials theft very laborious. You can change shell settings like font size, cursor blinking and font colouring with some tinkering and spending time reading Secure Shell help file.

A few native terminal features missing are X11 forwarding, SFTP to upload or download files, Syslog (data logging for auditing) and you can’t call multiple terminals but you could obtain a background process running in the shell account with the screen command for multi tasking.

It would not make sense to have this extension in a Linux computer, since all Linux OS come with a terminal. Windows users are the ones who should be thankful that there is no need to install CygWin any more in their computer, Secure Shell brings simple Unix access to the browser,

Visit Chrome Secure Shell

17 June, 2013
Build a VPN-Tor proxy on Amazon cloud servers with Lahana

Lahana is a set of scripts that can quickly create a VPN on Amazon EC2 cloud servers using Linux instances and tunnel everything through the Tor proxy network. It defeats state level Internet censorship, thwarting DNS poisoning used in the Great Firewall of China and blocking of websites by ISPs blacklisting URLs. The only way to stop Lahana is by barring access to all of Amazon EC2 servers which would leave the whole country without a cloud platform used by many companies providing different services or censors could block a single node and play a whack-a-mole game where the user gets access to a new Lahana proxy node from someone else everytime one of them is blocked.

There is no need to install any software for the user, Lahana can be used in Mac OS X, Windows, iPhone and Android, it should work on any device with a built in IPSEC client able to set up an L2TP VPN tunnel,. VPN node credentials can be publicly shared or only given to trusted individuals. The developer’s explanation to use Tor as exit node instead of Amazon servers IP is to protect the operator running a VPN on Amazon EC2 from abuse, if anyone commits a crime with the a Lahana VPN it would lead back to a Tor IP address and not the VPN operator. Lahana VPN sits in the middle in between the user and Tor in the form of User>>Lahana VPN>>Tor>>Website.

Lahana VPN Tor proxy on Android phone

Lahana nodes also serve as bridges and can be used to access hidden Tor websites, the more Lahana VPN nodes there are up, the faster the Tor network gets. This tool solves the Internet censorship problem but not privacy or anonymity, it would very easy for a Lahana VPN operator to log your computer IP and see what sites you visit and capture usernames and passwords, for high Internet anonymity you should only use Tor.

Visit Lahana homepage

11 June, 2013
Portable Private Browsing by PortableApps

Private Browsing is an open source portable app that works in conjuction with your portable Firefox copy. While Firefox already has a private browsing mode that will not save what sites you have visited, cookies, passwords, downloaded items or search entries and run completely in RAM memory not caching files in the hard disk, Private Browsing by Portableapps comes preconfigured with all of that and a couple of privacy plugins, FlashBlock and AdBlock Plus using the EasyPrivacy tracking list to block scripts and invasive sites.

Firefox Portable Private Browsing PortableAppsfox

After trying Portableapps Private Browsing app I found few advantages over configuring your Portable Firefox browser yourself, other than saving time. The app could also be improved disabling the default setting of sending data to Mozilla about your browsing “so that they can improve your experience“, with the actual configuration you will be prompted about what you want to do, another setting that should have been changed are the default Google and Yahoo search engines, the app would be better off unfolding non tracking search engines like StartPage or DuckDuckGo, you can change them yourself but it fails Private Browsing aim of reducing privacy configuration to zero.

The only unique features this app appear to have are that it will ignore local plugins, for example, if the computer you are working on has Java and Flash installed, the plugins will not work with your portable browser, and Firefox portable will not store a profile listing what sites you visited. Check out my list of the best Firefox addons for computer privacy if you need ideas to set up a custom private browser and add them yourself manually.

Visit Private Browsing by Portableapps

9 June, 2013
Self-erasing chat conversations with OTR browser extension

Off The Record messaging is a browser addon for Chrome (Firefox and Internet Explorer coming soon), to automatically erase messages you send to your friends or co-workers after they have been viewed. When someone receives or views a photo sent with OTR they have five seconds before it self-destructs, this default setting can be changed to a longer period of time if you wish so. You have to register your email address and a password to install the plugin, then you will see a bright OTR button on the top right corner of the browser, you need to add contacts or send invites by email before you can communicate, only other OTR users in your contact list and with he same plugin installed will be able to read the messages.

A small window opens when you click on the OTR button, big enough to write a few hundred words, photos can not be attached, they have to be taken with the computer camera.

Off The Record browser plugin self-erasing messages

This is a very basic plugin in features and security, not suitable for high privacy, anyone can take a screenshot or photo of the message and preserve it, it will only be of real benefit to avoid exposing personal messages by accident by keeping them off email services that archive all conversations, e.g. Gmail. Off The Record browser plugin target public are company workers who don’t want the boss to learn what they are gossiping about in the office, it could do the trick for that purpose, but it will not keep a very determined boss or IT administrator from learning what messages are being exchanged, a packet sniffer is all someone would need to spy on you since there is no mention of encryption anywhere in OTR specifications.

You should not confuse this plugin with the excellent Pidgin OTR plugin for Instant Messenger, they both have the same name but are very different.

Visit Off-The-Record homepage

5 June, 2013
Learn cyberwar skills online playing CTF365

Capture The Flag CTF365 is a realistic cyberwar game built for hackers, system administrators, security specialists, programmers and anyone with an interest in computer security

After signing up for the game you will be named a Combatant and asked to join the country you wish to fight for, each country can have many teams comprised of in between a minimum of five hackers and no more than ten. Teams can ally with each other to defend and attack a Fortress, members of the hacking team will have to safeguard their server while being on the offensive, when a user breaches another team Fortress the points go to the whole team. There will be a Hall of Fame with prizes for the most skilled hackers.

In this Capture The Flag contest the team’s server will run all major Internet services like SMTP, IMAP, FTP, one Content Management System with plugins for social media, embedded video and others, two different Internet browsers, three web applications and two different databases, part of your job will be to secure all of them.

Hacking game Capture The Flag CTF365

The game first campaign will mimic a National Agency network where you can play offensive security attacking their servers, as part of the attack strategy, you can DDoS another players virtual servers if you wish so, just like in real life. There is a CTF365 IRC server accessible from within the game, you can use it to find other players and start building your team or join others. There are only two rules, one, do not use the infrastructure to carry out real hacking attacks against non players, and rule two is do not launch a distributed denial of service against the game servers, if you break any of those rules your account might be terminated.

Capture The Flag is a superb way to get real hands on experience for penetration testers and sys admins defending their network, anyone with interest in computer security will benefit of this game emulating real life hacking scenarios, the aim is to have hundreds of targets in virtual machines that can be attacked at any time and for Capture The Flag to last a full year, there are future plans to offer Infosec companies the possibility to set up their own CTF contest to train students.

Visit Capture The Flag CTF365

3 June, 2013