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Attack by ZmEu

Who is ZmEu?

An image showing ZmeuThe name Zmeu (no capital E) is the name of a fantastic creature of Romania. There are so many stories that there isn't a clear understanding of what it is... but it is human like, can spit fire and wants to marry young women.

If you're wondering, it is generally a bad guy.

ZmEu Attack

Today, I noticed a lot of traffic on one of my servers. Looking into what was happening, I immediately found out that an attacker was looking for a loophole in that system. That attack was being performed from China.

Lost SSH key graphical prompt and auto-add to SSH agent

At some point in the past, my system somehow lost the ability to avoid asking me for my key every time I connect to one of my servers. It generally okay, I don't do so much work on that server that I'd have to connect all the time...

However, it is annoying when, once in while, I end up doing a lot of work, back and forth.

The ssh-agent was installed and working. I could add the key manually:

ssh-add ~/.ssh/my-secret-key
ssh-add -l

The ssh-add command allows you to add and remove keys from the ssh-agent. The -l command line option lists the keys currently held by the agent.

...

Supermicro X9SCI/X9SCA, video is gone!

As I am still trying to get my computers to work with a dual seat (or multiseat), I did an attempt in using the onboard video (a relatively decent Matrox card.) So I went in the BIOS and changed the setup for the video from Offboard to Onboard. Big mistake!

The video stopped working. On reboot the computer beeped 8 times and booted the OS normally (I have SSH setup so I could access the computer, but absolutely no video on either port: on board and off board.)

I have a Supermicro X9SCI/X9SCA. Searching for "no video" or "missing video on boot"... returned nothing ...

Cannot connect my Host system to Cassandra running on my Guest VM

I found a different way which is to use the:
Local Network or Host-only Network on your Virtual Machine

Today I did my first full install of Snap on a VM in my Ubuntu development system that runs VirtualBox.

This took me about 1h between getting all the files ready from our own APT repository, and then finding out all the setups needed (we have a few working installations, but we added all the necessary magic with time and did not clearly document all the steps yet... argh! so much to do!)

At some point, I wanted to setup the "domains" and "websites" tables on the VM. ...

Adding a group for to a logged in Linux user

Once in a while I want to add my user to a group and then right away make use of that group.

Unfortunately, in general Unix kind of forces you to re-log in for the new group to be attached to your account.

However, a command has been added, a while back, to do just that on the fly. Not something you would want to use in a script, but at least, it works for me when doing a few things here and there.

In my case, I wanted to run QEMU, which I hadn't done in a while, and the system told me that it could not open the KVM, the error: kvm permission denied.

The problem was that I was not part ...

List ciphers currently used by Apache2

If you are using Apache and e-Commerce, you probably want to know all the details of the ciphers used by the Apache SSL module.

So listing Apache supported ciphers is done using nmap as follow:

nmap --script ssl-cert,ssl-enum-ciphers -p 443 secure.m2osw.com

This call gives you a complete list of all the ciphers currently accepted by your running version of Apache. For example, the list may look like this:

| ssl-enum-ciphers:
|   SSLv3:
|     ciphers:
|       TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA - strong
|       TLS_DHE_RSA_WITH_AES_128_CBC_SHA - strong
|       ...

Repair a Cassandra Cluster

I use the Cassandra database cluster system to manage a new set of websites and once in a while I start getting many errors and the website stops working altogether.

When that happens, it is likely that Cassandra broke something in the temporary tables that it holds. The only way to go past that problem is to clear those tables. Until then, it will fail over and over again (they really would need some euristic to auto-clean up even if it means that you're losing some data.)

The command to repair the database, really quick, is as follow:

nodetool scrub snap_websites files

Note that ...

nvidia_XXX.ko No Such Device

Today I got a new video card because it looks like the old one I had was going bad. I hope that was not my KVM, although we'll see when it gets hot again, whether the video goes bouncy again or not... If not, then the old card is good for the trash (although it works in console mode just fine!)

So I got a new card. My old one was a NVidia GT 220. Fairly old model. Yes.

The new card is an NVidia GT 630 (to be precise: Asus GT630-SL-2GD3-L.)

When I tried to start X11, I saw an error (really quick) and the system did not come up. Looking closer into the matter, I could see that the NVidia ...

Why are my "vim: ..." commands not activated?

I use gVim all the time, I like that editor very much (emacs is just way too much, if you ask me.)

But once in a while I install a new server and by default they generally turn off the modeline feature. This is because there are potential security risks in link with that feature (i.e. vim starts running whatever script is defined in the text files that you edit...)

Anyway, I most often forget about the command to enable my:

vim: <setup>

(I most often define the tab stops, corresponding shift width and eventually the syntax of a file.)

Only, on those new servers, that doesn't ...

HP Printer options not offering "Color: Off" option anymore

As I upgraded to Ubuntu 13.10, I noticed that I lost the option to turn off the color when printing.

Looking around all the available options, no one to make it black and white (although the old option was saying something like: Color: Off; it was somewhat weird.)

Now that option is completely gone. There is no way for me to turn off my HP Printer color when I am in Acrobate or LibreOffice. I searched on the Internet to see whether that was just HP trying to get you to use colors on your printer or whether the option was available... somewhere else.

Indeed, I had to go to the System ...

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  • Gibbon
  • Heron

    Name of a Walt Disney character used for a version of Ubuntu.

  • LVM
  • views

    A module Drupal that let people define lists of nodes, blocks, feeds, and whatever other data available in your Drupal installation.

  • vsftpd

    Very Secure File Transfer Protocol Daemon, an FTP server that allows people to transfer data between computers. It is marked as very secure, at least it is as secure as an FTP server can be (although there has been several security advisories for this tool...)

    Remember that an FTP transfer is rarely using an encrypted pipe (it is possible to use kerberos and SSL to really secure the data transmission) and also because it uses a data stream opened dynamically, it is possible for hackers to spoof a data connection.