Suramya's Blog : Welcome to my crazy life…

December 20, 2007

PDF Editing & Creation: Open source alternatives to Adobe Acrobat

Filed under: Computer Software,Interesting Sites,Knowledgebase,Tech Related — Suramya @ 12:43 PM

I personally don’t like using PDF files. They are bulky and need extra software for me to view them. Plus they are a pain to export into html (which I like). But they are a necessary evil especially if you are dealing with the corporate world/goverment where most of the forms etc are in PDF format maybe because they allow the creator to choose the layout/content and make it hard for others to modify without spending a lot of money. Atleast that used to be the case, now there are most than 50 alternatives to Adobe Acrobat that you can try out and use for free. The following site has a listing of all the tools with a brief description of each: 50+ open source/free alternatives to Adobe Acrobat.

I regularly use Open Office to create PDF’s that look good. I have also tried using the PDF creator but didn’t keep it as Open Office took care of all my PDF creation needs.

Check out the list. You might find the some tool that will save you a lot of money.

– Suramya

December 17, 2007

Ping Tunnel – Send TCP traffic over ICMP

Filed under: Computer Software,Knowledgebase,Linux/Unix Related,Tech Related — Suramya @ 10:56 AM

This very interesting application allows you to tunnel TCP traffic over ICMP. Basically if you are behind a firewall that doesn’t allow any TCP data to pass through but allows you to ping systems on the net you can use this to create a tunnel over which you can send any data.

Check it out here: Ping Tunnel – Send TCP traffic over ICMP

Sounds very useful and is something to keep in the toolbox.

– Suramya

November 2, 2007

How to disable the ‘Run As’ option in Windows

Filed under: Computer Security,Knowledgebase,Tech Related — Suramya @ 12:13 PM

In Windows 2000 the ‘Run As’ option was introduced, the premise was that you would login as a regular user and if you needed to run a particular program as a different user or an administrator you would use it. Basically it duplicated the su functionality from the Unix/Linux world.

Now if for some reason you want to disable this feature, follow these steps:

For standalone Windows XP machines in a workgroup environment, you can disable Run As by hacking the Registry. Simply use Regedit.exe to locate the following key on each machine:

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer

Then create a new DWORD value named HideRunAsVerb and assign it a value of 1.

In a domain environment, you can disable RunAs using the Software Restriction Policies feature of Group Policy. To do this, open the appropriate GPO in the Group Policy Object Editor and locate the following node in the console tree:

Computer Configuration/Windows Settings/Security Settings/Software Restriction Policies

Right-click on this node and select New Software Restriction Policies, then right-click on Additional Rules and select New Path Rule. Now type the path to runas.exe and make sure the policy is set to disallowed.

If you prefer to apply this policy to specific users instead of computers, use a GPO linked to an OU where the user accounts reside and configuring Software Restriction Policies using User Configuration instead of Computer Configuration, such as:

User Configuration/Windows Settings/Security Settings/Software Restriction Policies

Source: Disabling the RunAs command

More detailed version: Disable RunAs

– Suramya

Identify what files are being used by a given process/TCP connection

Filed under: Computer Security,Knowledgebase,Tech Related — Suramya @ 11:54 AM

In linux if you want to know what files are being used, all you have to do is run the lsof command which shows a list of all open files and the processes that opened them. So if you want to figure out what program is using that insane amount of RAM you can run lsof and grep by the process ID to find it.

In windows however there is no such command so we have to use alternative methods. If you are trying to identify a TCP connection you can try running “netstat -bv” (Without the quotes). It will give you the executable behind process, something like:

TCP fury:2433 imap.perfora.net:imap ESTABLISHED 2724
C:\WINDOWS\system32\mswsock.dll
C:\WINDOWS\system32\WS2_32.dll
C:\Program Files\Mozilla Thunderbird\nspr4.dll
C:\Program Files\Mozilla Thunderbird\thunderbird.exe
C:\WINDOWS\system32\kernel32.dll
[thunderbird.exe]

For Windows XP and 2000 systems you can also download Fport, which is a free tool that will show you what programs on your system are opening which ports.

Hope this helps.

– Suramya

October 19, 2007

List of sites where you can get Information Security related news

Filed under: Computer Security,Interesting Sites,Knowledgebase,Tech Related — Suramya @ 12:40 PM

Here’s a small list of sites that security related news/resources:

This list is not a comprehensive list. I may add more sites as and when I find them.

– Suramya

How to find out who deleted a particular file

Filed under: Computer Security,Knowledgebase,Tech Related — Suramya @ 11:35 AM

If you want to know who deleted a particular file in Windows 2003 all you need to do is enable auditing the folder you want to keep track of. Just right click on the folder, go to “sharing and security”, then “security” tab, at the bottom click on “advanced”. Select the auditing tab, click add, select the group or users to track, then pick what actions you want to track.

To track file deletion you would enable:

Create files/Write data Success/Fail
Create folders / append data Success/Fail
Delete Subfolders/Files Success/Fail
Delete Suceess/Fail

Once thats done Windows will log all the information in the security event log.

– Suramya

October 11, 2007

UK Police Can Now Demand Encryption Keys

Filed under: Computer Security,News/Articles,Tech Related — Suramya @ 12:18 PM

Under a new law that went into effect this month, it is now a crime to refuse to turn a decryption key over to the police. So lets say you have an encrypted file on your computer and you are traveling through UK, if the cops feel like it they can force you to hand over the decryption key. If you don’t comply you face a 5 year sentence in jail if the investigation relates to terrorism or national security, or up to two years in jail in other cases.

But what they don’t seem to have considered is that sometimes people do forget passwords and keys. Back in 2003 I went through a phase where I started encrypted all my data backups (MySQL database dumps etc) using PGP for a couple of months, which was all well and good. Then I had to upgrade my OS so I formated my computer managing to loose the decryption key which was stored in my PGP keyring. I do have a physical copy of the key but thats sitting in one of the boxes in storage. So if I went to UK and they asked me for the key I can’t give it to them because I really don’t have it. But if I tell them that I will end up in jail for 2 years if the judge refuses to believe me.

So I think I am staying away from UK for the time being.

Thanks to Schneier on Security for the news.

More information available at The Register

– Suramya

October 3, 2007

Automatic session logging/monitoring with GNU screen

Filed under: Computer Security,Computer Tips,Security Tutorials,Tech Related — Suramya @ 11:10 PM

Found this good article on how to setup screen on Linux/Unix so that it automatically logs all activity made in the session. Screen is a utility that I use very often on my Linux box. Basically its a program that you start and it attaches to a specific console and if you ever get disconnected you don’t loose your work/position, all you have to do is log back in and reconnect to that screen. You can also connect to a system via ssh/telnet and start a program then disconnect from ssh then move to another location and reconnect to server and join the same session from there. I use it all the time when compiling stuff or downloading large files.

The main issue I had with screen was that it would only keep 20-30 lines in the history so if you wanted to scroll up to read the previous logs you couldn’t. Now this article explains how to set up logging so that you can do that. For the impatient here’s how you do it:

I wanted to automattically launch a screen session when somone logged in so if I happened to be on the server I could monitor them in real time. I also wanted a log of the session in case I wanted to look over it later or if I was not able to monitor the session live.

I ended up adding the following to my .bashrc

# — if $STARTED_SCREEN is set, don’t try it again, to avoid looping
# if screen fails for some reason.
if [[ “$PS1″ && “${STARTED_SCREEN:-No}” = No && “${SSH_TTY:-No}” != No ]]; then
STARTED_SCREEN=1 ; export STARTED_SCREEN
if [ -d $HOME/log/screen-logs ]; then
sleep 1
screen -RR && exit 0
# normally, execution of this rc script ends here…
echo “Screen failed! continuing with normal bash startup”
else
mkdir -p $HOME/log/screen-logs
fi
# [end of auto-screen snippet]

and add the following to your .screenrc

# support color X terminals
termcap xterm ‘XT:AF=E[3%dm:AB=E[4%dm:AX’
terminfo xterm ‘XT:AF=E[3%p1%dm:AB=E[4%p1%dm:AX’
termcapinfo xterm ‘XT:AF=E[3%p1%dm:AB=E[4%p1%dm:AX:hs:ts=E]2;:fs=07:ds=E]2;screen07′
termcap xtermc ‘XT:AF=E[3%dm:AB=E[4%dm:AX’
terminfo xtermc ‘XT:AF=E[3%p1%dm:AB=E[4%p1%dm:AX’
termcapinfo xtermc ‘XT:AF=E[3%p1%dm:AB=E[4%p1%dm:AX:hs:ts=E]2;:fs=07:ds=E]2;screen07′

# detach on hangup
autodetach on
# no startup msg
startup_message off
# always use a login shell
shell -$SHELL

# auto-log
logfile $HOME/log/screen-logs/%Y%m%d-%n.log
deflog on

Keep in mind that this is not a very secure setup. Anyone with any technical knowledge can edit the logs as they are located in the user’s home directory and are editable by them. So don’t rely on it extensively to keep a system secure.

Complete article is available here: Automatic session logging and monitoring with GNU screen for the paranoid.

Thanks,
Suramya

September 29, 2007

Joy’s of Windows XP

Filed under: Computer Software,My Thoughts,Tech Related — Suramya @ 11:47 PM

Windows XP is one of the most stable versions of Windows currently out there but it can also get to be very annoying especially to a Linux user. Things that are a snap in Linux are a pain to accomplish in XP and some things are just plain annoying. Below is a list of things that I find annoying in XP, if anyone knows a solution for any of them let me know.

1. Folder sorting doesn’t work if you add a new folder: I like my directories and files to be listed in alphabetical order sorted by file type so I have the ‘Auto Arrange’ checked with the system set to arrange icons by type. Now if I add a new folder/file to this directory it should automatically arrange the listing so that the listing is sorted, but that doesn’t happen. The file/directory ends up in the end of the directory listing. Refreshing the listing doesn’t help, I have to right click and choose ‘Arrange icongs by type’ before it sorts it correctly. This is damm annoying. In Linux (KDE) this happens automatically, at worst I have to hit F5 to refresh the screen to get the sorted listing.

2. Files/Directories get locked for no reason: I hit this one a lot. For some reason Windows randomly decides that a particular directory or file is in use (even though its not) and refuses to let me delete/rename it. It only releases the lock if I reboot the system. Which I don’t like to do often.

3. The auto-update doesn’t have a pause option: If you have Windows set for auto-updates and it decides to download a patch then you can’t pause it or cancel the download if you happen to need the bandwidth for other uses. Hit this a couple of times when Mom’s computer was downloading Windows updates and I needed to download a file on my laptop, the update was using up most of the bandwidth and my download was going really really slow but I couldn’t cancel the update.

4. The constant reboots: Windows needs to reboot for every little update that gets installed. Yesterday I switched on my mom’s computer and as soon as it started up and I logged in I got a message “An update has been installed that needs you to reboot the computer to take effect” (Don’t remember the exact words but it was something to this effect). How about that… I started up the system and it wanted me to reboot. I upgraded the Antivirus and installed the Windows updates on the system and it took a total of 7 reboots for it to make all the changes.

5. The virtual memory requirements: My laptop has a gig of RAM and usually I don’t run more than 3-4 programs at the same time (Editplus, Firefox and Thunderbird) though sometimes I also run Visual Studio and MS SQL server. invariably every few weeks I get a message stating that Windows is running out of virtual memory and is increasing the paging/virtual memory(?). I have gotten this message even when I was just running Firefox and Thunderbird. How can windows run out of a GIG of RAM when I am not running many programs? On my Linux box I run a lot more programs on a system with less RAM and still haven’t had any problems so far. I have burned DVD’s, watched a movie with 3-4 programs running at the same time without issues. Don’t dare do that on my XP system.

Ah well. Nothing is perfect. But atleast XP doesn’t crash often. I go for weeks at a time without having to reboot. Linux has its own set of annoyances but thats a story for another day/post.

Well this is all for now. Will post more later.

– Suramya

September 28, 2007

OpenDisc: Collection of open source software for download

Filed under: Computer Software,Interesting Sites,Linux/Unix Related,Tech Related — Suramya @ 8:15 PM

All regular visitors of this Blog know that I like Open Source Software (OSS) and whenever I get the chance I like to spread the word about them. Today I found out about OpenDisc which is a high qualiy collection of open source software (OSS) for the Microsoft Windows operating system (Most of them are available on Linux also) that can be used instead of propitiatory software.

You don’t have to download the entire CD if you just want a few particular programs, This section of their site lists all the programs they have on the CD and links to sites where you can download them directly.

Check it out. The less pirated software you use, the less the chance of getting your computer infected with a virus/trojan. If you are paying for legal software then this will save you a lot of money. Most propitiatory software on my system has been replaced with OSS alternatives so I can vouch for most of the software.

– Suramya

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