Geekblok

While I am studying for my RHCE certification I was reading about the Linux audit system. It is a real interesting subject and I am likely to write a small guide on that.

From the audit homepage there is a link to the article about audit log visualization of Steve Grubb. I was amazed of the simpleness of the code he uses for visualization of data. It apears that the code he uses is based upon the graphviz project. I didn’t know about the graphviz project, but it seems superb. I will get back on this subject in a later article. Now back to the study.

How much money do you make? Of course most of us know the answer to that question. We know how much we make, the horrible chunk the government takes from us and what is left per week/month. But do you have any clue how much money you make per second (or looking at this post)?

Cashto will tell you how much you make per day/hour/minute/second. Fun! (well … fun if you make enough)

For the third part in the guide, I’ll show the use of the escape_char and where it can come in handy. The default escape character in a openssh session is the tilde: ~. This might not be the best escape character together with your own keyboard layout. On some setups you must also use the space to get the tilde be a real tilde. Just test this in a xterm what you need to do to see an actual tilde. Otherwise, use the -e escape_char option, for example ssh -e '&' joffie.example.net.

After you have logged into the joffie.example.net machine, you can use the keystrokes & and . (dot), to close the connection. But there is more.

Read more »

Today I received one of those emails again:

Subject: **Message you sent blocked by our bulk email filter**<br /> Body: Your message to: &lt;h.bokking@some-domain.dom&gt;<br /> was blocked by our Spam Firewall.<br /> The email you sent with the following subject has NOT BEEN DELIVERED:<br /> Subject: October 70% OFF

Well… thanks but no thanks, postmaster at edutel.nl!

I can very well understand the message was denied by their “Barracuda Spam Firewall” : the message originated from Russia and the V-pills-word was included in the “From”-header, two reasons enough to mark a message as spam. But I was never the actual sender of that message, since the “From” was forged…

This is a common technique used by spammers, but to overcome this one should never ever BOUNCE spam!! There’s even a whole page dedicated to “Why you shouldn’t bounce spam and viruses“, explaining why it’s better to REJECT these kind of emails. A must-read for every so called postmaster!

I myself don’t reject, but DISCARD all spam-messages identified by SpamAssassin / amavisd-new into a separate folder for further analysis, so it gives me the opportunity to make some tweaks to the spam-filter itself.

ImproveYourImages.com is a simple looking website that can improve your images (hence the domain name, I figure). The three examples tell us that you can

# Restore true original colors
# Correct color temperature

# Adjust poor lighting

Especially the last one looks interesting to a bad photographer like me, so let’s test our own images on this!

Read more »