Introduction to Antispam Practices

According to a research conducted by Microsoft and published by the Radicati Group, the percentage held by spam in the total number of emails sent daily has been constantly growing since 2005. As a result, spam is expected to represent 77% of emails sent worldwide by 2009, amounting to almost 250 billion unsolicited emails delivered every day.

In a world where spam is bound to hold such an important position, methods of preventing it should also be given an increasing importance. Some of the easiest and most widely used prevention methods are host control solutions, Antispam applications and user education.

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How To Block Spam Before It Enters The Server (Postfix)

This is just a quick guide showing you how you can configure Postfix (2.x and 1.x) to block spam before entering the server. It's more or less self-explanatory. However, after applying this to your own mail server, you should check the mail log to make sure that no legitmate mails are blocked.

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How to Check if Your WebMail Account has been Hacked

Normally when someone compromises a WebMail account they'll pilfer through all your messages and save anything they're interested in keeping. Unless the intruder is really dumb, and sometimes they are, they'll change all the messages back to unread (bold) so you won't notice their presence. What you can do ahead of time is set a kind of a virtual silent alarm on your account. Here's how.

Regla de iptables para bloquear MSN

Los brasileños del sitio Dicas-L encontraron una simple y muy satisfactoria regla de firewall para bloquear el servicio de mensajería instantánea de MSN en toda una red. Para esto es necesario el módulo STRING de iptables disponible a partir del Kernel 2.6.14. La regla es la siguiente:

iptables -I FORWARD -p tcp -m string --string "VER " --from 51 --to 56 --algo bm -j REJECT

Y su explicación es la siguiente...

Wireless networks: The burning questions

Wireless networks might be mainstream across enterprise networks, but that doesn’t mean they’re no-brainers. Here, we’ve raised and attempted to answer some of the thornier questions you might still be dealing with.

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FreeBSD Project Integrates Support for the Camellia Block Cipher

The FreeBSD Project has integrated support for the Camellia Block Cipher, developed by Nippon Telegraph and Telephone Corporation (NTT) and Mitsubishi Electric Corporation. Camellia has been specified for use with IPsec, SSL/TLS, S/MIME, and XML.

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Encrypt and sign Gmail messages with FireGPG

Gmail may be an excellent Web-based email application, but there is no easy way to use it with privacy tools like GnuPG. The FireGPG extension for Firefox is designed to solve this problem. It integrates nicely into Gmail's interface and allows you to sign and encrypt not only email messages but also text snippets from any Web page.

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Debian as a desktop system

Debian is well respected as a stable server distribution, and most of the reviews focus on aspects appropriate to server deployments. This article covers Debian on the desktop. It is not a step by step tutorial, but focuses on the highlights of the recent Etch release.

FreeBSD/xen

As people might have noticed, it's been awfully quiet here. That is mostly because I've been so damn busy with my new project: FreeBSD/xen. I assume people will know what Xen is, if not, wikipedia is your friend :-)

Quite some time ago, Kip Macy has been working on the port, but eventually started working on other things. I'm trying to continue his work, and currently, most of it will be in the Perforce branch. Mind that the current focus is the domU support (ie. using FreeBSD as a guest OS), but dom0 (using FreeBSD as the host OS) is of course also TODO :-)

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RealPlayer: One-click Video Ripping

RealPlayer is coming up with a free version which will allow one-click video ripping.
This free downloadable video player will allows anyone to save and organize video files in all major formats including Flash, QuickTime, RealMedia and Window Media and will support video ripping from websites like YouTube or more.

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A New Global Memory Card Standard

The MultiMedia Card Association has approved a new memory card standard called the Multiple Interface Card (miCard). The card will make transferring pictures, songs, and other data between electronic gadgets and PCs easier. Twelve Taiwanese companies are preparing to manufacture the new miCard.

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NetBSD 'Quarterly' Status Report Published

The NetBSD Project has published the first 'quarterly' status report in 2007, covering the months January through June of 2007. This status report summarizes the changes within NetBSD from January until June 2007.

BIND 9.4.1 imported to FreeBSD

After extensive testing, I've upgraded the BIND in the base to version 9.4.1. This version contains a lot of performance improvements, especially for threading, so I've re-enabled it by default. The other most significant thing in this version is improved DNSSEC, which will of course be of interest to only a few of you (unfortunately). :)

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Transfer files securely with SFTP

File Transfer Protocol (FTP) was once the most widely used protocol for transferring files between computers. However, because FTP sends authentication information and file contents over the wire unencrypted, it's not a secure way to communicate. Secure Copy (SCP) and the more robust SSH File Transfer Protocol (SFTP) address this security concern by providing data transfer over a fully encrypted channel. You can use these alternatives for transferring files securely over the Internet or any other untrusted network.

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10 Anti-Phishing Firefox Extensions

For most Internet users, defending against phishing attacks is a top priority. Typically, phishing attacks involve phony emails and fraudulent web sites that try to lure users into disclosing user names, passwords and other personal information, such as credit card numbers and social security numbers.

The damage caused by phishing attacks ranges from loss of access to your web account to identity theft. Once the personal information is obtained, the phishers may use one’s details to steal money, create fake accounts etc.

One popular way to combat phishing attacks is to maintain a list of known phishing sites and to check web sites against the list. This hack highlights 10 anti-phishing Firefox extensions that can be used to mitigate the risk of being a victim of a phishing attack.

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PHP 5.2.3 released

With the new version of PHP, version 5.2.3, the developers have fixed multiple security-related vulnerabilities. According to the release notes, it includes fixes for an integer overflow in the chunk_split() function and a possible path traversal bypassing path restrictions in safe mode resulting from a bug in the realpath() function, plus resolution of a vulnerability in the imagecreatefrompng() function that might cause it to enter an infinite loop.

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