Dan Q

Tag: technology

On The Importance Of A Firewall

This is a graph showing the average amount of time between port scans against Windows boxen, and it’s change from last year to this year. It’s down from 40 minutes to 20 minutes over the last year.

If we take this and assume a few things:

(a) There will always be Windows security vulnerabilities – not an unreasonable assumption in a large piece of software like Windows, or any similarly large program.

(b) Windows security vulnerabilities will always be discovered and exploited long before they are patched by Microsoft – based on past experience, this is a fair statement.

(c) All of the script kiddies doing this port scans are knowledgeable in the most recent exploits against Microsoft Windows – a little pessimistic, perhaps, but with a several-month-long window (ahem) in which to exploit them before they get patched, acceptable.

Therefore, it can be assumed that a new Windows XP PC needs only to be online for 20 minutes before it becomes infected with a ‘push’ virus, contaminated with a trojan, or enslaved as a zombie. On a slow dial-up modem connection, that probably isn’t quite long enough to download a copy of ZoneAlarm…

Jeez. Thank Dog for SP2.

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Executable Stenography… With A Difference

Somebody’s come up with a program that hides secret messages in executable programs. Well… that’s not so impressive – we’ve all hidden secret messages in JPEG files before by using programs to ‘flip’ certain pixels (example). This works by changing the image in subtle ways that the human eye won’t detect, but that the descrambling application will. But here’s the clever bit…

Typically, when encoding a ‘hidden message’ in an executable, one ‘pads’ the file, making it bigger. The technique used when encoding messages in graphics files can’t be used with executables, because ‘flipping’ bits of the file would stop the program from working (or at least, working as it should), which may arouse suspicion. But this new tool works by exploiting redundancy in the i386 instruction set, swapping instructions or blocks of instructions for other ones which are functionally identical. As a result, the original filesize remains the same, and the program maintains full functionality. It would take an eavesdropper to fully compare the executable with a known original executable in order to determine that there was even a message hidden within it, and (thanks to Blowfish cryptography) yet more effort to decode that message.

Marvellous.

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Thrashing

Thrashing is a computer science term referring to an undesirable occurrence in multiprocessing systems.

When a processor is given multiple jobs to do, it services them a little each in a round-robin fashion (assuming that no priority system is in effect), until each is done. This is, of course, actually significantly less efficient than doing each job one at a time, but doing a little of each job, a little at a time is more productive when dealing with humans, who like – for example – their web page to download at the same time as they write a Word document.

Unfortunately, optimizations to this system can cause it to go wrong. By giving the processor more and more jobs to do, it eventually passes a critical point at which it is spending more time performing administrative tasks and managing it’s ’round robin’ scheme than it is actually performing the tasks you want it to. You’ve probably seen a system doing this. The solution, of course, is to either stop giving the system jobs to do until it can finish some of those it already has, or, better still, to kill some of the running processes to enable the processor to catch up on it’s workload. The solution is not to click irritably on the buttons, or repeatedly demand more and more of the processor.

Today, I feel like a thrashed processor.

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How To Keep Up With The Latest Happings On Scatmania (or What Are All Those Pretty Buttons?)

If you’re looking for a way to keep up-do-date with the latest Scatmania happenings, it’s now really really easy. I’ve enhanced my weblog with a heap of useful syndication tools that make keeping track of my latest activities a doddle, even for those of you who are unenlightened and can still be caught using an awful choice of web browser.

You may have noticed that at the bottom of the Scatmania menu there’s a series of button. Most of these buttons (the top five) relate to subscribing to Scatmania, like this:

RSS RSS is a popular format for syndicating news and views on the internet, supported by most weblog communities and applications, as well as by many news sites. To view RSS content, you will need an RSS Aggregator such as Pluck (a plug-in for Internet Explorer), RSSOwl (for most operating systems) or the attractive NewsMac for MacOS. The Opera web browser now supports RSS feeds, too, and it looks likely that other browsers will soon follow suit.
  • The RSS : Journal feed from Scatmania provides you with the latest blog entries, as they happen.
  • The RSS : Comments feed collates the newest comments and replies to my weblog entries.

RSS is a great way to keep up with your friends weblogs and your favourite news sites.

Atom ATOM, like RSS, is a simple way to keep up-to-date with your favourite sites. Just download an ATOM-enabled newsreader (some, like BottomFeeder, can read RSS feeds as well) and point it at the sites you want to watch. Scatmania publishes an ATOM feed of the latest blog entries.
ESF ESF is a small, fast, and simple new way to publish content like weblogs. There aren’t really any programs for reading it right now. Why not consider writing one (see how simple the data format is).
CDF CDF, developed my Microsoft as part of Internet Explorer 4, was supposed to be the future of the way we used the web and subscribed to the services of web sites… but it never took off. However, Internet Explorer to this day provides the means to subscribe to ‘active channels’, and for Internet Explorer users, this may be the easiest way to keep up with Scatmanian events. Just click the button in Internet Explorer and Scatmania will be added to your Favourites list as a submenu, automatically adding new items (and removing old ones) as new entries are added to the blog. Thanks to Aquarionics for suggesting this reincarnation of Internet Explorer ‘active channels’.

So, now you’ve got no excuse for not being up-to-date with my blog… or anybody elses!

The other buttons are mostly just me showing off because I can write standards-compliant code – click on them and see for yourself.

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1984 Revisited: What If Apple Took The ‘Microsoft Route’

Daring Fireball has an article about “Apple vs. Microsoft” with a difference. Contrary to many, he argues that if Apple had taken the ‘Microsoft route’ in 1984, with their hardware and software (significantly superior to IBM-PC platforms running Microsoft software), by licensing the platform, they wouldn’t necessarily be the market leader today. It’s a well-written and compelling article, and if you’ve any interest in OS politics or parallel universes, it’s worth a look.

SURGEON GENERAL’S WARNING: Competing Directly Against Microsoft May Be Hazardous to Your Company

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Windows Security

Just recieved the following error message from Windows, while trying to connect to a shared directory elsewhere on the network… have never seen one like it before, so I thought I’d share it with you:

Windows Error Message: The System Detected A Possible Attempt To Compromise Security. Please ensure that you can contact the server that authenticated you.

Oh, so now I’m a hacker? Thanks, Windows.

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Computer Hardware For Sale: Bargain Prices

Overclockers Australia is running an article, collecting together advertisements for computer hardware and software over the last quarter of a century. I’ve pulled out a few of my favourites:

  • 1989 Tandy 500 MC Professional – only $8499; VGA graphics, 386/20MHz, 2MB RAM – this computer’s a real beast: and what a bargain!
  • Late-80’s Portable Computer – just $2295; 8" (monochrome) screen, CP/M (w/ WORDSTAR, MAILMERGE, and SUPERCALC). Has 64K of RAM and not one but two floppy disk drives (double-density)!
  • Looking to increase your hard storage space (this means you, Paul)? There’s a 10-MB Hard Disk (sold in 1981) for the sweet price of $3398! Yes, that’s 10 megabytes, not gigabytes. About the same size as a modern desktop computer CD-ROM drive, and with a slower seek time.
  • TRS-80 Model 16 (wonderful piece of hardware) for just $8499: 128K of RAM, dual-processors (one MC68000, one Z-80), multi-processing, page-capable memory model, optional 8MB HDD, two serial and one parallel port, and an 80×24 character 30.5cm green screen. Add a second floppy drive for just $500 more!

Those offers sound fresh! I think I’ll see if I can get a trade in against Duality…

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64-Bit Columbine

Toy… Phill from work has gotten himself a sweet new AMD64 processor; I went round to help him install it after he thought he’d broken it during assembly (turns out he’d missed a power lead and hadn’t fully locked the processor into it’s socket). Jeez; those 64-bit processors have a heap of pins (as one might expect). Runs pretty cool, though.

Claire, Paul, Bryn, and I watched Bowling For Columbine yesterday evening. Most of us’d seen it before, but it’s worth a second look. We came to the eventual conclusion that Michael Moore‘s films are all about the shock value, and that his books carry a far more meaningful (and less biased) examination of the topics… and that this choice was made because to get through to the “stereotypical American white male”, he feels that you need to shock them with a film. Would his books get to the people who he felt needed them without the films to ‘get the foot in the door’.

Gonna be a long week at work.

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Reb’s Back

Looks like I am making a regular reader out of Reb, my ex-. She posted another comment today. This time I’d improved the trace algorithm already (mostly out of curiosity). She’s connecting from her Tiscali IP (80.40.255.212). There’s no (meaningful) firewall running on the connection, and ports 439 (DASP), 445 (Microsoft-DS) [that could be interesting], 1723 (PPTP), 2001 (DC), and 6001 (X11:1) are open for incoming traffic (although the first two are filtered). Interesting that there’s a PPTP and X11 server running at that IP… looks like it’s probably a business server. Might see if I can probe it a little further… that wide-open port 445 looks like an interesting entrance…

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Making Progress

Claire’s at work this Saturday morning, so I’m taking advantage of the oppertunity to finish the web site I’m developing for my dad – almost got a deployable version ready, which is nice, because I could do with getting his feedback on it and (assuming all’s well with design and whatnot) deploying it “live” on Monday morning. Which is all good, because I need the money!

The folks who now own the cafe below us – our new landlords – have made great strides in getting it ready for use. It’s now got tables, and chairs, and a chiller unit, and some stock, and a coffee maker, and all kinds of stuff. It’s been entirely repainted and refloored and redecorated. It’s pretty much ‘there’. They’ve even put up the new sign. The new sign advertises the cafe’s web site, mgees.com. I’ve taken a look… and… it would appear that they tried to make a web page in Microsoft Word (bad start), then ran the source code through a copy of Dadadodo to ensure that it was completely mangled, before they uploaded it. Jeez. Still, they’ve asked me to quote them for a new one, so once I’m done with this site for my dad I’ll see what I can do for them.

Speaking of Dadadodo, Claire‘s been playing with it recently. You should see what happens when you put the book of Genesis through it… oh; we laughed.

Back to the code…

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A Win For A Sensible Web Browser

I’m making progress with the people I work with. I’ve now got six of the eight folks in our office using Opera (they were formerly using Microsoft Internet Explorer, and some of them have tried Mozilla Firefox. Perhaps my recent spate of ‘blog posts criticising Microsoft’s browser – combined with the various hacks I’ve been showing them that I can use to exploit an IE terminal – has had some part in this.

Just Phil and Sarah left who still use IE as their primary browser. Think I’ll install Firefox on the sly and see how long it takes them to notice.

Win. R.

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Dadadodo Poetry

Decided to have Dadadodo, which I used yesterday, to generate some poetry based on my vanity pages from the old version of AvAngel.com, my perpetually-under-redevelopment web site. Take a look at this:

My body, of the religion,
That of seeing myself in a moment,
Stares ahead.
Always been an existential touch,
And I banish this.
My life, without a link, is in my writing,
To her I’m water,
At the rain comes ecstasy:
It’s gone.

Not bad for an algorithm with no pre-programmed understanding of language, I thought. Meaningless… but in a good way…

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