Your computer and iptables

Written by Saran on August 27, 2010

If you are using Linux and you have been wondering what you can use to make your system secure via a firewall, you could try out tools with graphical user interface and all those other stuff. In any case, there’s also another method: using iptables.

What are iptables?

iptables are used by system administrators in creating rules for packet filtering, as well as NAT modules. It might seem a little too weird for those who have not much experience on the command line but this is essential so that people would be able to make sure that they are secure, especially if they are connected. Sometimes you never know what’s going on in the background, right? But with tools like this, you’d manage.

There are different states of connection and the nice thing about iptables is that it monitors the state of the connection. It could do redirects and modify or stop data packets. Because of its ability to detect the state of the connection, it is considered as better compared to ipchains.

Making rules

The system administrator makes the rules for the iptables. These rules determine how to deal with network packets. They are grouped into chains.

a. filter table – For filtering packets, obviously.
b. nat table – This sets up how rewriting ports and packets.
c. mangle table – Does it sound terrible? Mangle? But as the name implies, there is some mangling involved because it adjusts packet options.

The thing about these chains, these rules is that the packets that go through these chains would be evaluated according to the rules.

As one of the people I know have told me, you must make sure that you check out the settings of your computer first. Before you even think about downloading anything, make sure you are not vulnerable to some attacks that could happen. Make sure that the important ports are closed and that you’re in stealth. Stay tuned for more IT security tips and news to help you in your everyday life.

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Categories: IT Security Basics, Network Security

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Office policies and IT security

Written by Saran on August 20, 2010

office compliance

In every office, you have to have some policies when it comes to sharing of files and downloading of files. Why? For one thing, those computers are the company’s resources. And it should be that during work hours, people ought to limit their downloads except for materials that are necessary for their work to get done.

How do you formulate your policies when it comes to these matters?

If you are working in a creative environment, anything could be used as your inspiration. That is why there are companies who allow surfing within office hours and it does not really matter what sites you visit. Although some of them do block some sites that are mainly of the personal nature like Friendster, My Space and other similar sites. There are also some that ban blogging services like Blogger. They would even issue memos regarding the matter.

If you work in a strictly confidential project, it would be difficult to try to make sure that nothing leaks out. If you are connected via the Internet, chances are your works could be intercepted in one way or another by hackers. So you have to be careful that you have firewall activated. As others would say, just block off everything except interoffice email.

Employees must be briefed carefully so that they will not be surprised in case they were surfing the ‘net one time and they find out that there are blocked sites. Also, you have to make sure you observe how the employees work. Those in the financial business would have to guard a lot of information. They would have to ensure that the employees understand the policies and that they would follow them in order to ensure that everything will be secure. After all, it is better to be safe than sorry. You would not want to lose your valuable clients.

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Categories: Real-World Issues, Security Policies

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Europe to Enjoy Enhanced Data Service Center Security Courtesy of NTT

Written by Saran on August 19, 2010

Businesses – especially large multinational companies – rely heavily on data center services. With practically everyone depending on technology to carry on their businesses, this is but part of the natural progression of things. Of course, there is always the issue of security; and that’s where entities like Secode AB come into the picture.

Secode AB is a company that specializes in managed security services, or MSS. As a matter of fact, they have been at the forefront of this industry in Europe for many years. They’re known for providing high quality managed data center service, and earlier this month, another big player entered the playing field.

NTT Communications, which is definitely one of the most recognizable names in the world of technology, communication, management solutions, etc., has acquired Secode AB. The acquisition was announced earlier this month, although the exact terms have not been released to the public.

What is important is that northern European customers who have a great need for security services for data centers will be enjoying the benefits that both companies can offer. With all the resources of NTT backing Secode AB up, businesses operating in northern Europe can be more assured of 24/7 services to deal with the ever present security threats. Some areas that are covered include intrusion detection and prevention, log management, vulnerability analysis, data-loss prevention, anti-virus and anti-spam, managed VPN/firewall, and mobile security.

This development is sure to be welcomed with open arms by concerned parties all over Europe.  Current Secode SEO Trygve Reinertsen will continue to head the new subsidiary.

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Categories: Network Security, News, Storage

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You and your passwords

Written by Saran on August 13, 2010

password

There are different ways of creating passwords for your computer and online accounts. It seems like these days, the usual six characters as length of passwords is not enough. There are sites that when you sign up and you give your desired password, they will let you know whether or not your password is strong. Most of the sites that have it even point out that it is better to have characters that are more than six characters long. For another, they usually recommend that you have numbers and letters in your password. Mixing up uppercase characters along with it is also recommended. Sounds tough, right? Because the the passwords would seem random or something like it.

Here are some tips from different people so that you could have more secure passwords that you could easily remember:
1. Use two words with six characters each.
If you have two words, you have a twelve character long password. But here’s the clincher. You have to make some funky code that you would be replacing some of the letters with numbers. So it could be that every two letter you could replace the letters with numbers that have some signifance or maybe some random numbers.
There are people would use the names of their pets and something else that is totally random and those are combined by mixing the letters, alternating each letter.
2. Use some other language and make a phrase. Then turn it into leet speak.
It is similar to the first suggestion. However this takes it a step further because it will involve other countries’ languages. It is as if you are writing code indeed.
3. Have around three sets of passwords.
Rotate among these three passwords that you have. And change your passwords every so often. At least this makes it more difficult for others to find you your passwords.

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Categories: IT Security Basics, Tips

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RSS, blogs and security

Written by Saran on August 7, 2010

RSS icon

Blogs are popularly being read on RSS aggregators these days. That or via Atom feeds and recently, it has been said that attackers could use Javascript to take advantage of this. According to an article on USA Today, this could be any kind of information as long as it is in this format. In the said article, you could also find out the list of vulnerable readers: Bloglines, RSS Reader, RSS Owl, Feed Demon, and Sharp Reader.

This kind of news is actually not so new. Mark Pilgrim was one of the bloggers who has written about this before. He even set up an experiment of sorts, wherein subscribers to his blog feed saw a screen full of platypi. He has mentioned in his blog entry that the difficulty with RSS is that there is a lot of arbitrary HTML and it could include Javascript — it could be malicious Javascript as designed by some attackers. Mark Pilgrim even listen down the elements that should be stripped off by RSS readers, just to be safe:
script tags, embed tags, object tags, frameset tags, iframe tags, meta tags, link tags, style tags, style attributes from every tag.

If you are always subscribing to different blogs, forums and mailing lists through RSS, you should be careful about it. If there are comments RSS, you could also take precautionary measures by not subscribing to it. It is possible to get attacked through the RSS of comments. Aside from that, if you have set up your own personal aggregator, make sure that you have a ‘smart’ aggregator which strips off the said tags. If you have an aggregator on your computer, check if it is vulnerable. Maybe you could install something else that isn’t prone to attacks via RSS. It is better to be secure after all.

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Categories: IT Security Basics, Malware, News, Tips

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