Tag: reset

  • Services.exe running at 100% CPU and using 100s of MB of memory – Windows XP SP3

    I came across an interesting one in the last few days. This system was a Windows XP system with current updates – SP3, IE 8…. and among other things there was a complaint of very sluggish behavior. I updated the antimalware software installed and ran scans. Malware Bytes antimalware actually found and removed two suspect files, but that didn’t seem to sole the sluggishness. The web browser (internet explorer) would take what seemed like a minute or so to respond to any action. One thing I discovered is that Internet explorer 8 can behave VERY slowly if there are a lot of sites in the restricted zone. (Spybot S&D immunization puts lot’s of sites in restricted zones.) So, I found a way to remove them all and retry and things seemed quicker, but… after running for 15-20 minutes the system really started to become unresponsive and so I had to start looking for another cause…. services.exe was running at 99% cpu or 100% cpu from time to time and the memory footprint was growing – the high mark I saw was 350MB of memory in use for it (!)

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  • The great firewall of China

    The great firewall of China may be just an illusion in technical terms. This article describes the details of how things work…. Basically when “banned content” is detected, both ends of the connection are sent a flood of tcp reset packets. Which (if both sides are designed to pay attention to) means that the two computers “hang up” assuming the other side reset the connection. But, while most current PC operating systems obey the reset packets…. it’s not something that is imperative. (You might think of this as a targeted/surgical denial of service attack using TCP reset packets…) The article goes a bit deeper though….

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  • NTFS cloning

    Sometimes drives just go bad. Surprise. One recent fresh install of Windows XP had started having real stability problems. On running a chkdsk and looking at the event viewer, it was fairly clear that 16KB of bad sectors and the disk problems had likely been the problem (lots of disk and atapi errors in the system log. Mostly disk error during paging operation (swap filing)) So…. I looked at cloning the drive using dd_rescue. All went well and the new system booted up on the new identically sized drive. In fact EVERYTHING was fine except chkdsk still reported 16KB of bat sectors….

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  • The D-Link DWL-800AP+ as a wireless repeater to extend wireless range – Part 6

    Ok, so here’s the synopsis… I’ve spent the last few articles setting up a D-link DWL-800AP+ as a repeater for a linksys WAP11 (v. 1.1) As of the end of the last entry I had a bit of a problem with WEP but that seems to have been resolved now and here I am to fill you in on what went wrong. It was really a simple mistake. When I copied and pasted over from the linksys….

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  • The D-Link DWL-800AP+ as a wireless repeater to extend wireless range – Part 2

    For starters, I hooked the D-link DWL-800AP+ up and connected it through a crossover cable to my usb network card. That way I could access it exclusively on one adapter and look online for information with the other adapter, which came in quite handy. The first thing I found was that by default the dwl-800ap+ was configured to use 192.168.0.30 as it’s IP address. This one was not configured with the default settings. (Used / via ebay….) So, I did an nmap -sT 192.168.0.* -e eth1 which scanned the whole 192.168.0. list of addresses using my eth1 adapter (as opposed to the default adapter eth0)

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  • Global White Space Reset (CSS/html)

    This may not be useful to many people, but I thought it was interesting. If you do web design and use css you’ll probably like this… I found this post at leftjustified.net about a neat way to “reset” the padding and margin css information which can help for designing sites to display the same when using CSS. Unfortunately, many browsers have little quirks in displaying css, maybe they have strange default settings which cause css placement to look, well, strange, from one browser to another… in comes this little trick…

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  • Bad week for Cisco, security headaches

    For starters, there was this advisory last week in response to a planned talk at a hacker convention on the possibility of a cisco router ipv6 exploit. The advisory detailed a LOCAL exploit and not the remote exploit that the talk was centered around. There was legal action against the speaker and materials detailing it were destroyed (literally ripped out of notebooks) at the convention by Cisco. Apparently this is the kind of vulnerability that could “shut down the internet”. Of course, much of the internet’s backbone runs on Cisco equipment. Next….

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