Computer Tips -Tech Info

Tag: proxy

  • Filtering out Ads with a Proxy using SafeSquid Proxy Server

    I just ran across this good how-to on replacing ads using a proxy server (in this case safesquid). A proxy server is a piece of software that requests web pages for other machines and then passes the pages along to the other computers. When the server requests a page it’s possible to make alterations and this is exactly what the how to details. In this case they construct a rule to identify ad blocks in the page (by the text that they use to call the ad from the adserver). After the block is identified it’s replaced with a custom bit of html.

    Good how-to and I wanted to make note of it for future reference.

  • Windows XP repair install problems

    I’ve run into a few problems with a windows xp repair install in the last few days that I wanted to detail the problems and what the resolution was. First, it was someone elses laptop needing a hard drive replacement. The drive was imaged, but windows still would not boot, so I broke out the XP Pro disc for a repair installation *(after trying to chkdsk from the recovery console first and fixboot /fixmbr…) Anyway, I went through the repair install process and the system booted up just fine. My next task was windows update and here’s were I started running into problems. Typing an address in the address bar of internet explorer caused a new window to open, which seemed to hang. Opening the home page seemed fine (i.e. the page that loads when you first open explorer), but you couldn’t navigate to another address.

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  • Torbutton – firefox anonymity browser extension

    I don’t know if anonymity is exactly acheived, but…. anyway not too long ago I explored/setup tor on my system to play around with, no real reason I suppose, but doing what I do it pays to be aware of many different kinds of software. Tor proxies web requests from your machine through a tunnel to another machine on the tor network – it could be nearby or far away, but it essentially prevents the destination site from knowing EXACTLY where you’re located and can prevent machines in the middle from logging your access (i.e. your isp, or a wireless access point owner.) The problem is – once it’s setup you have to turn it on by changing the proxy settings in your browser – tedious. Well, in comes torbutton, which is a firefox extension to enable routing through tor with the click of a mouse. (You do have to have it setup beforehand (tor and privoxy work well together for that.)

  • Caching downloaded deb files with apt-cacher

    It seems silly with multiple machines to download the same file multiple times. At some level it’s not THAT inconvenient. It really depends on your connection speed and the size of the files in question. For Ubuntu and other systems based on the .deb package format and apt-get there is a nice option for setting up proxy’ing to allow a single download of deb files for install on multiple machines. That option is called apt-cacher. There’s a good wrietup here on the setup of this cache -ing software.

  • The problems with cache servers

    Networkworld brings us this report that exploit code removed from websites can live on for quite a while in caching servers. Which, in a way is NOT news, but it’s worth remembering. Many times when someone visits a website, their really visiting a caching proxy server that has previously grabbed a copy of data from the original website. Many networks use cache servers to improve network performance. (i.e…. we have 20 people an hour hitting cnn.com why shouldn’t we just be able to download the page once?)

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  • Good sarc monitoring tip

    Sarc is still in their month of security tips per day and todays is another good one. Todays tip is about monitoring machines, particularly those that “defend” your network. (Mail antivirus scanners/ proxy fitlers/scanners/etc.) The core of the advice is to not just ping – that only tells you if the system exists and is online – it doesn’t tell if things are working. They suggest scripting tests (antivirus scanner can be tested via the EICAR test signature for instance.) They note that doesn’t tell if the av scanner is updated (I prefer a crontab output of the days updates – looks like there were around 9 clamav signature updates yesterday.

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  • Symantec Antivirus Remotely Exploitable Vulnerability

    This is bad – whose defending the defender? eEye security has a bulletin announced that regards a remotely exploitable vulnerability in Symantec Antivirus 10.x and Symantec Client Security 3.x They say other versions MAY be vulnerable they’re waiting for information from Symantec. Now, Symantec is probably the biggest selling antivirus package out there. It looks as though, from Symantec’s advisory, that the Norton Antivirus product line is not affected, ONLY “Symantec Client Security 3.1” and “Symantec Antivirus Corporate Edition 10.1”

    They have released IDS updates to try to detect attempted exploits of this….

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  • Using ssh to protect web browsing over wireless or other hostile networks

    This really could be used to encyrpt web traffic over any “hostile” network. Here’s what I’m talking about. Laptop using wireless. Within our internal network we would LIKE all our web traffic to be encrypted at least from the laptop to a wired host. (From there to the outside world it will be open.) At the minimum we would like to have the traffic encrypted over the wireless leg of the journey. Here’s the most straightforward approaches uing ssh.

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  • Federal Government funding research into VOIP wiretapping

    I can’t say I’m surprised, it makes sense. Plain old telephone service (POTS) can be tapped, and now that VOIP is coming into it’s own, the FBI and others need new ways of tapping the conversations. CNET is reporting on one such initiative that seems to be proving successful at the first step towards tapping a conversation taking place over Skype. Even one that uses an anonymizing proxy server.

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  • Kstars – great personal astronomy software under linux

    I’ve played around with Kstars off and on for a good while. It reminds me vaguely of a program I used to have under windows. It’s essentially a planetarium on your desktop. It is GPL licensed and part of the KDE Education suite of programs for the KDE desktop under Linux. It has all the basics for a program of this class (view the night sky and the stars from your latitude and longitude.)
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