Archive for the ‘Windows’ Category

Information exchange

Tuesday, July 14th, 2009

Today I was behind my computer when I received tweets about a severe vulnerability in Microsoft Office Web Components. Although it did not apply to me ( I am not using internet explorer, actually most of the time I am not even using windows ), I figured I had loved this way of information exchange when I was a network/system administrator in a previous job.

In a fairly big network it would have been plausible that every few hours a PC would be infected due to this vulnerability. So the faster the problem is known, the less damage could have been done to the client machines.

I can recommend any system/network administrator to sign-up for a twitter account and follow some security related persons / groups. Reading tweets costs time, but it will spare you time when something bad is on the loose.

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Posted in General, Vulnerability, Windows | 2 Comments »

Strange e-mail originating from exchange server

Monday, June 8th, 2009

Today a friend asked me to look at something strange he found in his logs.
To better understand the situation, I’ll describe his network setup:

He runs a linux server with postfix, spamassassin and clamav antivirus which removes all spam and virusses received from the internet. All legitimate e-mail is then routed to his exchange server. E-mail that is sent by users on his network is relayed back to the linux server and then sent to the destination.

Last week he was checking his mail logs on his linux machine and he noticed his box was receiving e-mail from strange e-mail addresses. He figured: Well, no surprise there: Probably spam messages. Until he looked at the ip address from which it originated: It was the ip address of his own exchange server. First thing he did was doing a full virusscan of his exchange server. Nothing. He tried some spyware scanners, but again: Nothing. So he called me.

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Posted in E-Mail, Linux, Security, Windows | No Comments »

Network problem turned out to be AD problem

Sunday, October 26th, 2008

Last week one of our stores had a problem with seemingly slow starting workstations. These workstations where hanging for at least 15 minutes on “Applying computers settings”.
The workstations that where affected at first seemed to be randomly.

Because the local admin had created a new master-copy a few weeks earlier, and he couldn’t remember whether the machines that where affected had received this new image I decided to first investigate the master before attempting to monitor the network.
All dynamic DHCP settings where okay, netsh int ip reset didn’t work, neither did deleting the whole network card and re-adding it.
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Posted in Cisco Switching, TCP/IP, Windows | 1 Comment »

Migrate / Merge two Active Directories

Tuesday, March 13th, 2007

A few weeks ago a customer came to me, and said: “Our Active Directory was fucked up while performing an upgrade from windows 2000 to windows 2003.” Because their Exchange was already set-up in a new environment, they wanted to merge the two ADs together; and thus all rights on their Corporate files ( 300 GB ) should change from the old user account in the old domain to the new user account.

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Posted in Migration, Windows | 1 Comment »