Chamadas grátis pela internet… com o VOIPBUSTER

O voIpBuster permite fazer chamadas grátis para a rede fixa portuguesa a custo 0, a versão normal é limita as chamadas a 1 minuto, mas se fizer o carregamento minimo 5 euros + impostos ficamos sem tempo limite nas chamadas para numeros fixos em Portugal.

Este programa e as intruções podem ser encontradas em http://www.voipbuster.com/en/index.html

Using your (stupid) neighbor wireless connection guide

Many people don’t know it, but they are open to getting free highspeed internet. This is simply due to the fact that they have a neighbor that is using wireless networking and has not properly secured there connection. With a few simple tools you can tap into your neighbor’s wireless connection and begin taking advantage of free high speed internet connection. Only one warning, it is not legal to hack into other people’s computers and steal stuff, SheerBoredom.net does not condone the use of these tools for hacking. These tools are only here to better help secure your wireless network. Essential Items:
1. Get a good browser, I prefer Firefox. Firefox is not only a good browser for surfing the web, but it is more secure and allows you to tweak your internet to go faster.
2. You will need a wireless network card. Any card should do fine, most networks are G, so a 802.11g card would be the best route to go, also probably the cheapest.Thats all the items you need to get started. The rest of the items are found below and links to them are found right above the picture of them.
Finding Wireless Networks
Locating a wireless network is the first step in trying to exploit it. There are two tools that are commonly used in this regard:

Network Stumbler a.k.a NetStumbler ““ This Windows based tool easily finds wireless signals being broadcast within range ““ A must have. It also has ability to determine Signal/Noise info that can be used for site surveys. I actually know of one highly known public wireless hotspot provider that uses this utility for their site surveys.

Kismet ““ One of the key functional elements missing from NetStumbler is the ability to display Wireless Networks that are not broadcasting their SSID. As a potential wireless security expert, you should realize that Access Points are routinely broadcasting this info; it just isn”™t being read/deciphered. Kismet will detect and display SSIDs that are not being broadcast which is very critical in finding wireless networks.
Attaching to the Found Wireless NetworkOnce you”™ve found a wireless network, the next step is to try to connect to it. If the network isn”™t using any type of authentication or encryption security, you can simply connect to the SSID. If the SSID isn”™t being broadcast, you can create a profile with the name of the SSID that is not being broadcast. Of course you found the non-broadcast SSID with Kismet, right? If the wireless network is using authentication and/or encryption, you may need one of the following tools.

Airsnort ““ This is a very easy to use tool that can be used to sniff and crack WEP keys. While many people bash the use of WEP, it is certainly better than using nothing at all. Something you”™ll find in using this tool is that it takes a lot of sniffed packets to crack the WEP key. There are additional tools and strategies that can be used to force the generation of traffic on the wireless network to shorten the amount of time needed to crack the key, but this feature is not included in Airsnort.

CowPatty ““ This tool is used as a brute force tool for cracking WPA-PSK, considered the “New WEP” for home Wireless Security. This program simply tries a bunch of different options from a dictionary file to see if one ends up matching what is defined as the Pre-Shared Key.Â

Source:http://www.sheerboredom.net/modules.php?name=News&file=article&sid=79Â Â

Crontab how to

Cron é em linux o equivalente ao tarefas agendadas do Windows, ou seja permite correr automaticamente em background, em intervalos predefinidos pelo utilizador, determinado programa ou script.

Crontab (CRON TABle) é o ficheiro onde são guardadas as tarefas agendadas(intervalo, comandos, etc…).

A seguir algumas luzes sobre o crontabs:

1. Crontab Restrições

2. Crontab Comandos

3. Crontab Sintaxe do ficheiro

4. Crontab Exemplo

5. Crontab Ambiente

6. Desactivar email

7. Gerar log do crontab

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1. Crontab Restrições

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Pode executar o cron tab se o seu endereço aparecer no ficheiro /usr/lib/cron/cron.allow.Se este ficheiro não existir pode usar o crontab se o seu endereço não aparecer no ficheiro /usr/lib/cron/cron.deny.

Se só existir o cron.deny e estiver vazio, todos os utilizadores o podem usar. Se nenhum dos ficheiros existir, só o root pode usar Crontab’s. Os ficheiros de premissões consistem em 1 username por linha.

2. Crontab Comandos

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export EDITOR=vi ;expicifica o editor que vai ser usada para editar o ficheiro crontab.

crontab -e Edita o ficheiro crontab, se este não existir então é criado.

crontab -l Mostra o conteudo do ficheiro crontab.

crontab -r Remove o ficheiro crontab.

crontab -v Mostra data da ultima alteração ao ficheiro crontab

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3. Crontab ficheiro

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Crontab sintaxe :-Â O Crontab tem 5 campos para especificar o dia, data e hora seguido do comando a ser executado

* * * * *Â Comando a executar

– – – – –

| | | | |

| | | | +—– dia da semana (0 – 6) (Domingo=0)

| | | +——-Â Mes (1 – 12)

| | +——— Dia do mes (1 – 31)

| +———– hora (0 – 23)

+————- minuto (0 – 59)

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* O valor valido para cada asterisco é o valor que está no intervalo entre parentises

A coluna pode ter o valor * ou uma lista de valores separados por virgulasÂ

Se tiver um * no campo das horas o comando será executado todas as horas

4. Crontab Exemplo

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Este exeplo remove o conteudo do directorio /home/lixo todos os dias ás 18:30

30 18 * * * rm /home/lixo/*

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5. Crontab Ambiente

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cron executa o comando do directorio de cada utilizador com a shell (/usr/bin/sh)

cron fornece algumas variaveis de ambiente e são elas:

HOME=Directorio do utilizador

LOGNAME=Nome do utilizador

PATH=/usr/bin:/usr/sbin:.

SHELL=/usr/bin/sh

6. Desactivar email

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Por defeito o cron envia um email ao utilizador que criou a atrefa. Se nao for necessario ou nao quiser receber estes emails basta acrescentar o seguinte no fim da linha do comando a ser executado Â

>/dev/null 2>&1

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7. Gerar um log dos crons

________________

Para escrever o resultados dos comandos para um log:Â

30 18 * * * rm /home/lixo/* > /home/lixo/limpar_lixo.log

Hello world!

E pronto o famoso Hello World já cá está, agora só falta começar a Bloggar….