Tech2know » {What is}

What is cloud computing and free cloud services offered by G.ho.st and iCloud

Tech2know — Sat, 05 Sep 2009 14:01:08 +0000

Now we have two website, G.ho.st and iCloud that are offering free cloud services. This is a very significant step in making cloud computing services available to all.

Before going ahead I would explain in brief about cloud computing. Well, all of us use desktops, laptops everyday to perform some task or other like editing a document, managing important documents on desktop etc. But, when you travel somewhere then you have to carry your notebook(laptop) with you to be able to access your desktop. Yes, you can use remote desktop software to access your desktop from somewhere else but the same is not always possible because of some limitations like it requires installation of the software on both the systems(your laptop at home and the system from where you want to access your laptop).

Here comes cloud services for help. Cloud computing services are in very initial stage and would not replace your desktops as of now at least but very useful for moving files from your home computer to your work compute and having your personal files with you no matter where you go. It is a computer in a browser and also called as WebOS.

Above is just a small example of the usage of Cloud computing. But, original idea of cloud computing is to load all the useful applications on a cloud(interconnected group)of web servers from where the applications can be accessed by a number of users like the way they access them on their desktop/laptops. In effect, installation of the application is not required on individual system/computer. The only piece of application which user’s computer require will be an interface(which would be a browser) to access cloud. It is an an emerging field and can take some time to reach at a level where it develops enough trust in individual users and big organizations to store their sensetive data on a cloud hosted by other company. After all privacy and security of data are the most important need for anyone. But, if it reaches to this level then all the heavy programs and number crunching jobs will run on remote cloud servers and user’s computer would require minimal configuration in terms of hardware(processor, memory etc) and softwares. Well, the truth lies in future and I cannot predict it. Till then I am going to use this for sharing files .

So, coming back to our original topic, after going through both G.ho.st and iCloud features I decided to create my account with G.ho.st because of the difference in the amount of file storage provided. iCloud offers 3GB of file storage while G.ho.st offers 15GB. G.ho.st also also offers an extra 5GB of storage for each person you refer. So, don’t forget to fill mani6dec in ‘Referred by’ box while setting up your account . Below is a screen shot of my G.ho.st screen :

Both G.ho.st and iCloud offeres open office suite for creating and editing Microsoft Office compatible files. G.ho.st provides editing of Excel via Zoho Sheets. Other services and applications includes :

1) Communication apps like instant messenger to chat to your friends(G.ho.st has multi-protocol instant messenger called Meebo) once you have added your friedns vis ‘Add Buddies’.

2) Sharing : You can upload and share the files with your buddies ot just make them public so that all users can view them.

3) Entertainment apps like MP3 player, Internet radios etc.

4) Photo editing : G.ho.st provides Snipshot

5) Widgets/Utility apps : Calculator, RSS feeds, Notepad(iCloud), Ghost notes(G.ho.st) etc.

You can visit the websites for more information.

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[What is] Google latitude

Tech2know — Sun, 26 Jul 2009 06:36:08 +0000

Google latitude is a software that allows you to share your whereabouts with famiy and friends through your mobile phones. It is a new feature in Google maps on user’s mobile device like iPhone and iPod touch . You can also use it on computer by adding it in your iGoogle as a gadget. Once you have opted in to Google Latitude in your mobile device, you can

1) Share locations : Location sharing starts only when both you and a friend agree. Invite friends via email or easily add them from your Gmail contacts.

2) Contact your friends : Quickly contact your friends with an SMS, IM, or phone call. You can also get directions to lead you to your friends.

3) Control privacy : You can share, set, hide your location – or sign out of Google Latitude – from the privacy menu. Your location is not shared with your contacts automatically. Location is only shared if you invite your friends to view your location and the good thing is that you can choose whoc can see your location. You can also hide your location or share only a city-level location with certain friends. When you hide your location, your friends will not see your photo icon on a map and will not see a location for you in their list view. When you select the city level sharing option for individuals, those friends will see your photo icon without an arrow beneath it and without an accuracy circle in the map view. Your photo icon will also appear in the middle of your current city location.

says Google. Check out this video to know more about privacy features of Google latitude.

Well, I personally feel that Google latitude will revolutionize the way we stay connected.

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What are Rootkits, How they work, software to remove them

Tech2know — Tue, 14 Jul 2009 03:26:05 +0000

Friends, this time I decided to write a short explanation about Rootkits.
Almost all of us must have encountered this term at some point of time. Specially, whenever talking or reading about any antispyware/antivirus utility. Though, most of us are quite familiar with terms like Viruses, Trojan Horses, Worms etc but for a few of us the confusion persists about rootkits.

So let me start with most basis question, what is a rootkit? Is it a virus, a trojan, a worm ? Well, a Rootkit is a program which is designed to hide itself, its related processes, files, folders, registry keys and other malwares(this is a short form of Malicious Softwares).

Now qustion arises that what can be the intent of deploying rootkits in a system?
To answer this, Malicious Rootkits(I am specifying maliciouse explicitly because the rootkits can be non malicious which do not pose any harm) are used to compromise security of a system but letting the deployer to gain remote control over a computer or network for criminal purpose. These rootkits serve the purpose but hiding the malwares which installs a backdoor allowing the attacker to gain access to the infected system. If the rootkit infect a user account with administrator privileges then it allows the attacker to gain unlimited access in the infected computer. This very clearly indicate the harm which a rootkit can do. Yes, it allow an attacker to steel your personal information or allow to install more malware which can leave your computer unusable.

Till now we have understood what are rootkits, what is the intent of deploying rookits and what harm they can do. Now we will dig a bit further to understand how a rootkit hide itself. Yes, this is quite important to understand. The trick lies in the ability of a rootkit to hook(or attach) itself with the operating system(windows) and make the operating system lie for them. In this way, rootkits deceive some traditional anti rootkit scanners. Whenever a scanner queries operating system, the rootkit ensures that the program gets manipulated information to hide its existance. In other words, it changes the program flow i.e whenever any scanner ask for some information from operating system, the rootkit’s own code is executed which provide maniulated information to the questioning program.

Now, a BIG question : But how a rootkit intercepts the program flow? Well, it does so by using a technique which is called as Hooking system function calls.In a very very simple words, hooking is attaching itself in a proper place so as to receive specific calls from the application program(eg. scanner) which asks for some information from operation system. Before we understand hooking, we’ll take a look at types of rootkits because the type of a rootkit will decide which kind of hook a rootkit can deploy.

Types of rootkits:

1) User mode rootkit :Let us take a look at the functioning of a user level program for better understanding. A user lever program cannot perform all the functions by itself. For example, a word processor is a user level program which helps you in composing text. when you save the document then the data is actually written to the disk but this write operation is a privileged operation and can be performed only by the kernel. Therefore, the word processor request the kernel to perform this operation. A user level program cannot interact directly with the kernal because kernel cannot understand the language of the application program. So, when you give command to a word processor to save the text, windows translate this command into a system call which in turn communicate with kernel. The system call generated by windows is the language to accomplish communication between application program(example a word processor) and kernel. This is called as Application Program Interface or API. Since, every application program uses a set of APIs for performing its task therefore it maintains a table in memory which contains addresses of the APIs. This is for improving the efficincy of the appliction porgram. So, for every operation which the application program can perform, there is an addess for the corresponding API stored in a tables. This table is called Import address table or IAT.Depending on the operation to be performed, the program read IAT table, fetches the address of the related API and calls it.

Now, it would be easier to understand what a user level or user mode rootkit is. A user level rootkit is a rootkit which have the privileges of an application program and cannot interect with the kernel directly. Like a user program it also has to interact via APIs. It has an access to all the data structure which recides in application program address space.

2) Kernel mode rootkit :Kernel is a part of operating system that always resides in the memory and manages all the processes in the system. It also control all the hardware, communication between various hardware parts, comunication between various applications. It also allocates resources to various requesting applications and also performs vital tasks like memory management, process scheduling, CPU scheduling. For performing all these tasks efficiently, kernel also maintain table containing important address information. These are the addresses of the native APIs or kernel level APIs which are called by kernel to actually perform the privilege operations like writing to disk, allocating resources to various requesting applications etc.

Now, it would be easier to understand what a kernel level or kernel mode rootkit is. A kernel level rootkit is a rootkit which have the privileges of kernel. These are most critical privileges because the rootkit can access any memory location, any hardware, any process in the system. Thus, results in a very dangerous impact becasue ultimately all the programs communicate with kernel in some way or other and hence kernel level rootkit can control anything or everything.

Now coming to hooking, both user level and kernel level rootkits use API hooking to make sure that operating system only return the result which doesn’t show their presence or hide them. User level rootkits hook into or we can say replace the address of an API with its own address in application program’s IAT(Import address table). For example,it may hook into an API which task manager calls to display the running processes and hide itself. Since, each application program has its own IAT therefore user level rootkit has to hook every program’s IAT to show system wide effect.
On the other hand, a kernel level rootkithooks the tables used by kernel(I was not able to find the specific name given to the table used by kernel). Since, this is a table which is used by all the processes in the system therefore it achieve the system wide effect by hooking in a single table. After hooking, any call to kernel level APIs will result in the execution of rootkit’s code(because rootkit has hooked in the table or we can say replaced the address of API with its own). Since most of the programs rely on he data sent to them by operating system’s therefore rootkits remains invisible to them and give the impression as if the system is clean. Since, these rootkits can access any memory location therefore these can overwrite the code of the kernel itself with their own code.

Now coming to the solution part,I would say that for removing rootkits completely, the scanner should have a capability to run in kernel mode. I am using superantispyware for the past 1 year and it has this capability. You can download this free from http://superantispyware.com. The free version doesn’t offer real time protection and automatic updates but will surely remove the rootkits in manual scan.

There are a few other good program which I personally prefer to have in my system if not superantispyware.

These are Spy sweeper and CounterSpy but these are not freewares therefore I have settled for superantispyware and I am quite happy on my choice.

Another excellent program is RootkitRevealer from Sysinternals. This is a very fine utility and I would have loved to have it in my system but it has some compatibility issues with Vista. But, if you have Windows XP then it is a must have for you. You can download it from Download RootKit Revealer. This utility only display the entries which might be infected. You need to examine all the reported discrepancies for ensuring that it is really a Rootkit which needs to be removed. Once you find that a Rootkit is installed, search web for removal procedure.

Note that, I already have other anti-virus apart from superantispyware which provides real time protection. One should never compromise on real time protection.

Unfortunately, none of the utilities on web can give you 100% guarantee in terms of removing Rootkits from a system. But, I personally prefer the one’s mention in this post because they are really good at the job.

With this I conclude my explanation about rootkits. I hope I explained the topic clearly and in simple language.

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GoogleDocs PDF Viewer

Tech2know — Wed, 08 Jul 2009 09:07:52 +0000

Google has yet again came up with a unique functionality which enables you to view PDF files without having Adobe Reader installed on your system. I used this for the first time and thought to share it with you. If you receive an email with attached PDF file and you do not have Adobe reader installed then don’t worry. Just open the email and click on ‘View’ beside the attachment. You will see that a new window opens up and show you the file in below format :

So, you can always send all of your pdf documents to your Gmail account and view them without having Adobe Reader in your system. Though sending PDF files to your Gmail account as attachment solves the purpose yet it is not the ideal way to make a repository of your pdf files because the files will become unmanageable as the number increases. The workaround for this problem is directly upload all the pdf files in GoogleDocs(http://docs.google.com). If you have a Gmail account then you can login into GoogleDocs by using same username and password as that of your Gmail account. Once you are logged in, you can very easily upload the file by using ‘Upload’ button and after uploading the file(cake.pdf) will look like following :

This feature enables you to make a repository of your pdf files which you can access, share and edit from anywhere from any system.

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