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Bypassing websense using proxy

by on Mar.27, 2012, under Internet

In many of the corporate and government institutions usage of internet is restricted using content filtering software’s like websense. Websense is commonly used software for content filtering and monitoring the internet activity so as to restrict the employees visiting the internet sites while at work. Websense is designed to block the site content in several categories like adult content, entertainment, drugs,  games, sports, peer-to-peer sharing, gambling, instant messaging, emails, health, illegal, job search, religion, travel, violence, weapons, advertisements, freeware, software download, pay to surf, malicious website and many more. The software also tracks individual internet usage for the purpose of collecting and reporting on any browsing deviating from the standards set by the library, government or other employer, and its reports can be data drilled by risk class, category, URL, application, user, workstation, dates, and more

The concept behind Websense is simple, whenever an employee attempts to visit a specific webpage; a request is generated and then passes through a firewall. Websense looks at this request and it allows or disallows the request depending on if the requested URL is in the Websense database. In transparent mode, Websense counts on the fact that the firewall will forward the whole request in a single time. If the whole request is not transferred at one time, Websense will allow the packet to pass, as the packet doesn’t look like a HTTP request. If you want to bypass Websense and browse any page, you can use several techniques to bypass Websense’s filtering and authentication process.

 

Bypassing Websense using a Web Proxy

One method used to bypass Websense is to use a web-based proxy site. With a web proxy, Websense sees you browse to the web proxy and not to the web site you are actually browsing to. You can browse to the web based proxy site, and then the web proxy browses to the web site you actually wanted to visit. The reason that these web proxies are able to bypass Websense is the ‘S’ in the HTTP address (https://) stands for secure connection and Websense does not block such secured connections. This is probably the simplest way to get around the Websense program as it takes little time and no one will wonder what you are up to.  To find a current web proxy, visit proxy page. 

 

Creating your own Web proxy

The constraint with the above practice is that the web based proxy site could be blocked under the category “proxy” in websense because these are commonly used proxy site. The alternate approach is that you can build your own proxy site if can afford for a web hosting. PHP Web proxy is an open source tool that can be deployed in your website and enable your website for web proxy access. Here the constraint is that you website could be blocked in any of the other categories mentioned above. For this you could make your website as HTTPS enable using RAPIDSSL or any of the cheap or free SSL certificates.

Bypassing Websense using HTTP Tunneling

You can also bypass Websense by using HTTP Tunneling. HTTP Tunneling programs work well to bypass Websense. Most programs also come with options, which help you to destroy the history of your Internet and Widows activity. What this means is that you can ensure comfort and security of your online activities and can spoof your web browser information. One can download HTTP Tunneling software programs from the Internet for free or inexpensively. HTTP Tunnel software consists of client-server HTTP Tunneling applications that integrate with existing application software, permitting them to be used in conditions of restricted network connectivity including firewall networks, networks behind proxy servers, and NATs.

 

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Splitting file based on line numbers in UNIX

by on Aug.22, 2009, under Unix

This script will be useful if you require to split a huge file based on number of lines or records. Normal file splitters available in the market split the file based on the size (byte, KB, MB) which cannot be used to split based on number of lines or records.

Steps to use the script:

  1. Save the below script as lsplit.ksh
    propDIR=./
    propFile=$propDIR/SSNRange.txt.prop
    inpFile=$1
    date
    startLineNo=1
    count=1
    while read line
    do
    startLineNo=`echo $line | cut -f1 -d,`
    endLineNo=`echo $line | cut -f2 -d,`
    if [ "$endLineNo" != "" -a "$startLineNo" != "" ]; then
    echo "Cut here from $startLineNo to $endLineNo"
    sed -n "$startLineNo","$endLineNo"p $inpFile > $inpFile.split.$count
    count=`expr $count + 1`
    fi
    done < $propFile
    date
  2. Create a properties file SSNRange.txt.prop which would contain the range of records or lines. Example of properties file is as follows

    1,400
    401,1504
    1505, 7000

  3. Run the script
    $ lsplit.ksh infile.txt

  4. Three output files will be created
    • infile.txt.split.1 –> Creates a file with first 400 lines
    • infile.txt.split.2 –> Creates a file with lines starting from 401 to 1504
    • infile.txt.split.3 –> Creates a file with lines starting from 1505 to 7000

Advantages of this script:

  • File is split based on line numbers are records.
  • No manual editing is required the correct the first and last records
  • Easy to handle it in batch

Courtesy: Santhosh Fabian

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Disabling compressed files (ZIP/CAB) search in Windows XP/Vista

by on Jun.11, 2009, under Windows

Windows XP / Vista have a built in feature of supporting compressed archive files. The file types supported are .zip and .cab. Windows treats these as folders and displays it in the windows explorer tree and also includes these files during the search. This would a hindrance to the users who had used their favorite compression utility like winzip, winrar or 7-zip in their previous versions of operating system. Windows file search functionality will be slow when there are lots of compressed files in the search folder. We can overcome this hurdle by disabling this feature. This can be later enabled when required.

For Window XP to Disable

1. Open start > Run

2. Type the command regsvr32 %systemroot%zipfldr.dll /u

3. Press ok on the popup message

4. The change will take effect immediately, but you may have to restart Windows for all features of the built-in ZIP support to disappear

For Windows XP to Enable

1. Open start > Run

2. Type the command regsvr32 %systemroot%zipfldr.dll /u

3. Press ok on the popup message

4. The change will take effect immediately, but you may have to restart Windows for all features of the built-in ZIP support to be available

Where %systemroot% normally is C:windowssystem32

For Windows vista to Disable

1. Open Start > Run

2. Type “regedit.exe and click ok

3. Navigate to the key HKEY_CLASSES_ROOTCLSID

4. Export the values under the key HKEY_CLASSES_ROOTCLSID{E88DCCE0-B7B3-11d1-A9F0-00AA0060FA31} and HKEY_CLASSES_ROOTCLSID{0CD7A5C0-9F37-11CE-AE65-08002B2E1262}

(This process is to backup those keys incase later if this feature needs to be enabled)

5. Delete the keys HKEY_CLASSES_ROOTCLSID{E88DCCE0-B7B3-11d1-A9F0-00AA0060FA31} and HKEY_CLASSES_ROOTCLSID{0CD7A5C0-9F37-11CE-AE65-08002B2E1262}

(The key keys HKEY_CLASSES_ROOTCLSID{E88DCCE0-B7B3-11d1-A9F0-00AA0060FA31} is associated with the zip file and the key

HKEY_CLASSES_ROOTCLSID{0CD7A5C0-9F37-11CE-AE65-08002B2E1262} is associated with cab files. In case you need to disable one of the feature zip/cab you can do it by deleting the corresponding keys.)

6. Restart the computer for the changes to take effect.

Alternate Method:

1. Download the reg file here

2. Double click to install

3. It is successful, restart the computer for the changes to take effect.

For Windows Vista to Enable

1. Open Start > Run

2. Type “regedit.exe and click ok

3. Go to File > Import and select the files that are taken backup in step 4 (For Windows vista to Disable).

4. On successful import, restart the computer for the changes to take effect.

Alternate Method:

1. Download the reg file here

2. Double click to install

3. It is successful, restart the computer for the changes to take effect.

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Closing telnet session without terminating the foreground process

by on Nov.04, 2008, under Unix

Finally have found out a way to terminate the telnet session with out killing the foreground process which is running. Anyone struck with the above situation can follow this 🙂

Assume a script “script1” is running in the foreground for a long time and this script needs to be retained even if the telnet session is closed. Here are the steps which needs to be followed.

  1. On the telnet screen press <CTRL + Z>. This will temporarily stop the script or process to run.
    $ ./script1.ksh
    [1] + Stopped (SIGTSTP)        ./script1.ksh
  2. Type in the command “bg” to run the process in background
    $ bg
    [1]     ./script1.ksh&
  3. Identify the session process ID. This can be done by giving the “ps” command in the prompt.
    $  ps
    PID      TTY   TIME  CMD
    4882522  pts/7  0:00 ps
    4984988  pts/7  0:00 -sh
  4. Identify the PID of the script which is is shifted to background. In our case “script1” This can be done by ps command piped with grep as below.
    $ ps -ef | grep script1.ksh
    user1 4399240 4984988   0 08:57:49  pts/7  0:00 grep script1.ksh
    user1 5029960 4829226   0 07:57:23      -  0:00 /usr/lpp/ars/bin/script1.ksh
  5. Now with all the PID’s collected, use “nohup” command
    $ nohup -p 4984988
    $ nohup -p 5029960

This will make the script or process not to be terminated even if the telnet session is closed.

NB: The telnet session process 4984988, will be running at the background unless it is killed.

Courtesy: Santhosh Fabian

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Customizing / Automating windows installation with nLite/vLite

by on Oct.26, 2008, under Windows

Installation of windows will not be a new thing for one who owns a laptop/computer with Windows OS running on it. This comes true when coming to re-installation too. Here is a way where you can make your installation much easier. A freeware tool nLite or vLite can be used to customize your windows installation to make it easier.

Advantages of nLite and vLite:

  1. These software are freewares.
  2. Windows service packs can be slipstream to the original installation disk
  3. The hot fix or patches can be integrated.
  4. Drivers can be integrated
  5. Customized boot can be created.]
  6. Installation can be made unattended by giving default values.
  7. Windows installation components can be added / removed.
  8. Registry tweaks can be done before installation.
  9. Burn it into a bootable image file or CD.
  10. Saves installation time and reduces manual intervention

Freeware usage:

nLite -> Windows 2000, Windows XP, Windows 2003

vLite -> Windows Vista, Windows 2008

*All editions of the above OS is supported.

How to use it?

  1. Download nLite or vLite from their official websites.
  2. Install the nLite/vLite package.
  3. Choose the location of original windows installation disk.
  4. Choose the modification that needs to be done in windows installation in the tabs Integrate/Remove/Setup/Create.
  5. Provide all the inputs as a part of customization.
  6. Finally burn it to CD/DVD.
  7. Use it for your future installation.

Note: The developers claim that not to get support from Microsoft for any installation errors which is created by nLite/vLite.

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Connecting to a hidden administrative default share in Windows Vista

by on Oct.11, 2008, under Windows

In windows vista by default the hidden default shares like c$, ADMIN$, IPC$ and Print$ are disabled due to User Account Control (UAC) feature avoiding it to be connected in the network. So when you try to connect from other computers in the network you might possibly get the below errors.

Logon unsuccessful:
Windows is unable to log you on.
Make sure that your user name and password are correct.

You may get the below error when you try to connect using “Net Use” command:

System error 5
has occurred. Access is denied.

How to get rid of it?

There are 2 solution for this problem

  1. You can create an explicit share of the required device.
  2. You can modify the registry to enable LocalAccountTokenFilterPolicy key.

Creating explicit share for the device:

  1. Open Explorer
  2. Choose the folder or drive
  3. Right click on the folder or drive and click on share
  4. If you have password protected sharing enabled, select which users can access the shared folder and their permission level. To let all users have access, select Everyone in the list of users. By default, the permission level is “Reader.” Users who have this permission level cannot change files or create new files in the share. To let a user change files, change folders, create new files, and create new folders, use the “Co-owner” permission level.
    If you have password protected sharing disabled, select the Guest account or the Everyone account. This is the same as simple sharing in Windows XP.
  5. Click on share and then press OK

This method is safe and can be done by beginners.

Modify registry to enable LocalAccountTokenFilterPolicy Key:

Here is also an alternate which requires some expertize in the operating system. Here are the steps.

  1. In Run prompt type regedit to open registry editor
  2. Browse through the following sub key
    HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionPoliciesSystem
  3. Create a new entry with the below information
    Key Name : LocalAccountTokenFilterPolicy
    Key Type : DWORD (32-bit)
    Key Value : 1
  4. Exit registry editor.

To disable this option modify the registry key value to 0.

Warning: If you are trying out this method user need to have a knowledge on windows registry. If some of the keys are modified incorrectly it may cause a serious problem to the operation system for proper functioning. Backup registry before doing any changes.

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Comparing two columns in excel spreedsheet

by on Sep.22, 2008, under Office

If you in a software service based industry you may get many questions in Microsoft Excel. One such question is “How to compare two columns in the excel if the data is in thousands of rows”. Here is a solution for it.

Imagine you have two columns A and B. Column A has the data which needs to be compared against column B. Here I would show you 3 excel formulas to archive this.

  1. MATCH
  2. COUNTIF
  3. VLOOKUP

Here is the syntax

  1. =Match( value, array, match_type )
  2. =CountIf( range, criteria )
  3. =VLookup( value, table_array, index_number, not_exact_match )

Here is a example usage :

  1. The below syntax can be used if we want to find out a match and mark the result as ‘Y’ or ‘N’ and consolidate it.
    =IF(ISNA(MATCH(A1,$B$1:$B$100,FALSE)),"N","Y")
  2. The below syntax is used to find the count of the matches in the resultant column. If the count is 0, then there is no match. If the count is 1 then there is 1 match. If the count is 2 then the matched data count is 2 and so on.
    COUNTIF($B$1:$B$100,A1)
  3. The usage below is similar to the first option where there is change in the function idiom
    IF(ISNA(VLOOKUP(A1,$B$1:$B$100,1,FALSE)),"N","Y")

Where to use what?

Now the question is, of all of them which performs the same function and now where to use what function. The MATCH/VLOOKUP can be used to find out the existence of the data in the column but COUNTIF can be used to find out the existence of data and to find the number of instances the data exists.

Which one is faster?

MATCH/VLOOKUP is more faster than the COUNTIF, since COUNTIF has to look up the entire array to throw out the count. But MATCH/VLOOKUP terminates it loop once it find the data in the array.

There are more functions too in excel for comparison of data. I shall explain it when I come across it.

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Disconnecting a hidden remote connection

by on Sep.21, 2008, under Windows

One fine morning I was surprised to see the error “Multiple connections to a server or shared resource by the same user using more than one user name are not allowed” when I was trying to connect a network drive. I  verified for network connection in  windows explorer but I could not find any connections. Here is a way to solve it.

1. Goto command prompt.
2. Type “NET USE” (with out codes) to view all the connections active or inactive.


Status       Local     Remote                    Network
-------------------------------------------------------------------------------
Unavailable  M:        \192.168.0.100Music     Microsoft Windows Network
OK                     \192.168.0.103m$        Microsoft Windows Network
The command completed successfully.

3. Type “NET USE \<remote_resource_name>” (with out codes and replace <remote_resource_name> with the actual name) to display the complete details.


Local name        Z:
Remote name       \<remote_resource_name>
Resource type     Disk
Status            OK
# Opens           2
# Connections     1
The command completed successfully.

4. To disconnect this resource use the command without codes as “NET USE \<remote_resource_name> /DELETE
5. Now you are available to connect the remote resource.

Here are the other ways to disconnect through GUI if the connection is visible.

If the connection is mapped to the drive letter.
1. Open the Windows explorer
2. Goto Tools and choose the option Disconnect Network Drive
3. Choose the drive letter and click Disconnect.

If the connect is not mapped to the drive letter.
1. Right click on MyComputer
2. Choose Disconnect Network Drive and it display the all the resources connected
3. Choose the resource name or the drive letter and click OK

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Reseting Windows 9x/2000/XP administrator password

by on Aug.30, 2008, under Windows

Forgetting things in life is more common, but some somethings you will not have any impact. Imagine you have forgot a windows administrator password. You are really into trouble. You can’t really find any one to make you to get into your system. But here is a way to reset it.

If you are the old version of windows the the problem is much simple. To reset a password in windows 98, there is nothing much complex since the there is not much tight security.

For Windows 9x

1. Boot the system in dos mode
2. Go the windows directory
3. Search for *.PWD file
4. Delete the *.PWD file.
5. Reboot it and now you are in with the blank password.

But on later versions of the windows the security features are made so complex that it involves some complex steps to reset your password in case you forget it.

For Windows 2000/XP

1. Get back you windows bootable CD. Boot it.

2. Proceed to the the screens until you get the option to a) install windows or b) repair windows

3. Press ‘R’ to repair windows and then choose the appropriate options until reboot.

4. Your machine will be back in windows GUI mode. You need to enter to the command prompt by pressing “Shit + F10”. This step differs for windows 2000 and XP.

  • For windows 2000 press “shift + F10” when you see the screen “Registering Components”
  • For windows XP press “shift + F10” when you see the screen “Installing devices”

5. Now you are in the command prompt. From here you need to invoke the control panel.

  • For Windows 2000, Type “control.exe” in command prompt
  • For Windows XP, Type “nusrmgr.cpl” in command prompt

6. Now you could be able to access control panel.
7. From there choose user management to reset your password.
8. Once done, close the control panel and allow the repair process to get completed.
9. Finally reboot your computer
10. Now you can be in with your new password.

Here is an alternate way too if you have a free distribution of Linux know as Knoppix. Here are the steps.

1. Download the free version of Linux from http://www.knoppix.org/
2. Download the a package to change the windows password from here
3. Install the package chntpw as below

Knoppix@ttyp1[knoppix]$ alien –to-tgz chntpw_.deb
Knoppix@ttyp1[knoppix]$ tar xvzf chntpw.tgz ./usr/sbin/chntpw
Knoppix@ttyp1[knoppix]$ mv ./usr/sbin/chntpw ./

4. Find the windows partition using the command

cat /etc/fstab

5. Mount the windows NTFS partition using the command

mount -o rw /dev/hdax /mnt/windows

    x – replaces with the numeric depending on the configuration

6. Change your directory where the SAM file is available

cd /mnt/windows/WINDOWS/system32/config

7. Run the command

chntpw -u administrator SAM system SECURITY

8. This will ask you to enter a new password for the administrator account.
9. Just hit enter so that blank password will be entered.
10. Write the changes when it prompts to do so.
11. Reboot your machine on your hard drive and log in to windows with blank password.

NB: The author is not responsible for any kind of misuse by the readers.

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Welcome to ExpertsHeaven

by on Aug.30, 2008, under Site News

How To? This would be a million dollar worth question when we get struck in midst of something. We here at HowTo blog are aiming to provide you better way of find quick answers. This blog is indented to provide complete howto guide on anything; almost everything. This would be useful for you to act quicker and reach your purpose.

You could also share your experience if you have come across on any which would be helpful for the others. You can either directly register or post your experience or in case of any problems in registering / if you don’t want to register to this site, you can very well drop a mail to howto (at) expertsheaven (dot) com so that the information is shared.

We are looking towards full support from all of you. We are hoping to build a better howto community.

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