GENERAL POINTS Remember you must keep to the allotted time. Plan to rehearse your presentation! It is very easy to misjudge timing unless you have had a full scale rehearsal. Think about the most appropriate format for your presentation. For example: would a PowerPoint slide show be more effective than a lecture? Do you need to display or circulate props? Should a Q&A session be included, or can you involve the audience in some other way?
MAINTAINING INTEREST Avoid simply reading out an essay. You may want to rely on a script, but remember one task is to maintain the interest of the audience. Your own experience will tell you that listening to someone reading for eight minutes is not very exciting.
Vary the tone of your voice.
Avoid speaking too quickly.
Maintain eye contact with people in all parts of the room.
Smile.
Be mobile if not too nervous; if stationary do not slouch or lean on the wall or table.
Avoid doing things which distract the audience, e.g. chewing gum.
USE OF AUDIO VISUAL AIDS Visual aids must be clear to all of the room. Check that the font size of any slide or projected transparency will be visible to people in the back of the room. If using a word processor to prepare these, a font size of 16 pt or above is recommended.
Slides are best used to display a few headings rather than the whole text of what you are going to say. Think of them as key points which you can use as prompts. Do not simply read the material off the slide: supplement or explain what is written.
Sketches, cartoons, maps, diagrams are all good visual aids; they also tend to hold interest better than text.
Overhead transparencies are best written in dark or black pen; only show the relevant section, gradually uncover as talk progresses; switch off projector when not in use.
If you need to use equipment, check whether it will be in the room. Otherwise, will you need to borrow it, e.g. from the library? Will you need extra power leads or power boards as well? Are all projection globes working? Make arrangements well ahead and check the equipment and your A/V aids before the presentation session.
Finally It is inevitable that you will be nervous but remember that everyone will be involved. Try to approach presentations as a team. You will obviously support your partner if you have one, but also support others whilst they are giving their presentations: listen and signal that you are listening; so that you know what is going on and can join in the discussion.
TEN "DO'S AND DON'TS" FOR A STUDENT PREPARING A PRESENTATION DO: 1. Lots of background research. Even if the information is not used in the presentation, it is useful to have as much knowledge as possible for the discussion and audience questions. It will assist your confidence too.
2. Be organized - prepare in plenty of time. 3. Structure your presentation. 4. Focus on the question set. 5. Obtain material from a wide range of sources. 6. Practice your presentation. This helps take away some of the embarrassment when it is for real, and enables you to check the timing. If possible, have someone sit in and give you feedback. 7. Use note cards. 8. Speak clearly. 9. Have eye contact with your audience. 10. Use clear overhead transparencies, or slides (large font size, use of bullet points etc.).
DON'T: 1. Leave research and preparation until the last minute. 2. Rely on one source of information. 3. Make it up. 4. Just hope that it will come together on the day without preparation and practice. 5. Have no notes to rely on if you get stuck. 6. Worry too much - it's not as bad as it seems. 7. Mumble. 8. Read from a script. 9. Rush the presentation by speaking too fast. 10. Go over the time allotted for the presentation.
1981 - The First Virus In The Wild As described in Robert Slade's history, the first virus in the wild actually predated the experimental work that defined current-day viruses. It was spread on Apple II floppy disks (which contained the operating system) and reputed to have spread from Texas A&M. [Side note: Thanks to a pointer from anti-virus pioneer Fridrik Skulason we know the virus was named Elk Cloner and displayed a little rhyme on the screen:It will get on all your disks It will infiltrate your chips Yes it's Cloner! It will stick to you like glue It will modify ram too Send in the Cloner! For more info on Elk Cloner see http://www.skrenta.com/cloner/
1983 - The First Documented Experimental Virus Fred Cohen's seminal paper Computer Viruses - Theory and Experiments from 1984 defines a computer virus and describes the experiments he and others performed to prove that the concept of a computer virus was viable. From the paper... On November 3, 1983, the first virus was conceived of as an experiment to be presented at a weekly seminar on computer security. The concept was first introduced in this seminar by the author, and the name 'virus' was thought of by Len Adleman. After 8 hours of expert work on a heavily loaded VAX 11/750 system running Unix, the first virus was completed and ready for demonstration. Within a week, permission was obtained to perform experiments, and 5 experiments were performed. On November 10, the virus was demonstrated to the security seminar.
1986 - Brain, PC-Write Trojan, & Virdem The common story is that two brothers from Pakistan analyzed the boot sector of a floppy disk and developed a method of infecting it with a virus dubbed "Brain" (the origin is generally accepted but not absolutely). Because it spread widely on the popular MS-DOS PC system this is typically called the first computer virus; even though it was predated by Cohen's experiments and the Apple II virus. That same year the first PC-based Trojan was released in the form of the popular shareware program PC-Write. Some reports say Virdem was also found this year; it is often called the first file virus.
1987 - File Infectors, Lehigh, & Christmas Worm The first file viruses started to appear. Most concentrated on COM files; COMMAND.COM in particular. The first of these to infect COMMAND.COM is typically reported to be the Lehigh virus. At this time other work was done to create the first EXE infector: Suriv-02 (Suriv = Virus backward). (This virus evolved into the Jerusalem virus.) A fast-spreading (500,000 replications per hour) worm hit IBM mainframes during this year: the IBM Christmas Worm.
1988 - MacMag, Scores, & Internet Worm MacMag, a Hypercard stack virus on the Macintosh is generally considered the first Macintosh virus and the Scores virus was the source of the first major Macintosh outbreak. The Internet Worm (Robert Morris' creation in November) causes the first Internet crisis and shut down many computers. CERT is created to respond to such attacks.
1989 - AIDS Trojan This Trojan is famous for holding data hostage. The Trojan was sent out under the guise of an AIDS information program. When run it encrypted the user's hard drive and demanded payment for the decryption key.
1990 - VX BBS & Little Black Book (AT&T Attack) The first virus exchange (VX) BBS went online in Bulgaria. Here virus authors could trade code and exchange ideas. Also, in 1990, Mark Ludwig's book on virus writing (The Little Black Book of Computer Viruses) was published. While there is no proof, hackers are suspected of taking down the AT&T long-distance switching system.
1991 - Tequila Tequila was the first polymorphic virus; it came out of Switzerland and changed itself in an attempt to avoid detection.
1992 - Michelangelo, DAME, & VCL Michelangelo was the first media darling. A wordwide alert went out with claims of massive damage predicted. Actually, little happened. The same year the Dark Avenger Mutation Engine (DAME) became the first toolkit that could be used to turn any virus into a polymorphic virus. Also that year the Virus Creation Laboratory (VCL) became the first actual virus creation kit. It had pull-down menus and selectable payloads (though it's reported to not have worked very well).
1993 - Stealth_boot PMBS Stealth_boot PMBS used a unique technique to operate. You caught it by booting from an infected floppy disk. Once installed, Stealth_Boot would install itself in extended memory, switched the computer into protected mode, and then ran a virtual V86 machine which DOS and programs would use. Basically, the virus existed between the operating system and the hardware.
1995 - Year of the Hacker Hackers attacked Griffith Air Force Base, the Korean Atomic Research Institute, NASA, Goddard Space Flight Center, and the Jet Propulsion Laboratory. GE, IBM, Pipeline and other companies were all hit by the "Internet Liberation Front" on Thanksgiving.
1995 - Concept The first macro virus to attack Word, Concept, is developed.
1996 - Boza, Laroux, & Staog Boza is the first virus designed specifically for Windows 95 files. Laroux is the first Excel macro virus. And, Staog is the first Linux virus (written by the same group that wrote Boza).
1998 - Strange Brew & Back Orifice; JetDB Strange Brew is the first Java virus. Back Orifice is the first Trojan designed to be a remote administration tool that allows others to take over a remote computer via the Internet. Access macro viruses start to appear (JetDB).
1999 - Melissa, Corner, Win95.SK, Tristate, Infis, & Bubbleboy Melissa is the first combination Word macro virus and worm to use the Outlook and Outlook Express address book to send itself to others via E-mail. It arrived in March. Corner is the first virus to infect MS Project files. Win95.SK, in April 1999, is believed to be the first viral HLP file infector. Tristate is the first multi-program macro virus; it infects Word, Excel, and PowerPoint files. Infis installs itself as an NT driver and then takes over some undocumented functions. Bubbleboy is the first worm that would activate when a user simply opened and E-mail message in Microsoft Outlook (or previewed the message in Outlook Express). No attachment necessary. Bubbleboy was the proof of concept; Kak spread widely using this technique.
2000 - DDoS, Love Letter, Timofonica, Liberty (Palm), Stream, & Pirus The first major distributed denial of service attacks shut down major sites such as Yahoo!, Amazon.com, and others. In May the Love Letter worm became the fastest-spreading worm (to that time); shutting down E-mail systems around the world. June 2000 saw the first attack against a telephone system. The Visual Basic Script worm Timofonica tries to send messages to Internet-enabled phones in the Spanish telephone network (later in 2000 another Trojan attacked the Japanese emergency phone system). August 2000 saw the first Trojan developed for the Palm PDA. Called Liberty and developed by Aaron Ardiri the co-developer of the Palm Game Boy emulator Liberty, the Trojan was developed as an uninstall program and was distributed to a few people to help foil those who would steal the actual software. When it was accidentally released to the wider public Ardiri helped contain its spread. Stream became the first proof of concept NTFS Alternate Data Stream (ADS) virus in early September. As a proof of concept, Stream has not circulated in the wild (as of this writing) but as in all such cases a circulating virus based on the model is expected. Pirus is another proof of concept for malware written in the PHP scripting language. It attempts to add itself to HTML or PHP files. Pirus was discovered 9 Nov 2000.
2001 - Gnuman, Winux Windows/Linux Virus, LogoLogic-A Worm, AplS/Simpsons Worm, PeachyPDF-A, Nimda Gnuman (Mandragore) showed up the end of February. This worm cloaked itself from the Gnutella file-sharing system (the first to specifically attack a peer-to-peer communications system) and pretended to be an MP3 file to download. In March a proof of concept virus designed to infect both Windows and Linux (and cross between them) was released. Winux (or Lindose depending on who you talk to) is buggy and reported to have come from the Czech Republic. On 9 April a proof of concept Logo Worm was released which attacked the Logotron SuperLogo language. The LogoLogic-A worm spreads via MIRC chat and E-mail. May saw the first AppleScript worm. It uses Outlook Express or Entourage on the Macintosh to spread via E-mail to address book entries. Early August, the PeachyPDF-A worm became the first to spread using Adobe's PDF software. Only the full version, not the free PDF reader, was capable of spreading the worm so it did not go far. September, the Nimda worm demonstrated significant flexibility in its ability to spread and used several firsts. While not new in concept, a couple of worms created a fair amount of havoc during the year: Sircam (July), CodeRed (July & August), and BadTrans (November & December).
2002 - LFM-926, Donut, Sharp-A, SQLSpider, Benjamin, Perrun, Scalper Early in January LFM-926 showed up as the first virus to infect Shockwave Flash (.SWF) files. It was named for the message it displays while it's infecting: "Loading.Flash.Movie...". It drops a Debug script that produces a .COM file which infects other .SWF files. Also in early January Donut showed up as the first worm directed at .NET services. In March, the first native .NET worm written in C#, Sharp-A was announced. Sharp-A was also unique in that it was one of the few malware programs reportedly written by a woman. Late May the Javascript worm SQLSpider was released. It was unique in that it attacked installations running Microsoft SQL Server (and programs that use SQL Server technology). Also in late May the Benjamin appeared. Benjamin is unique in that it uses the KaZaa peer-to-peer network to spread. Mid-June the press went wild over the proof-of-concept Perrun virus because a portion of the virus attached itself to JPEG image files. Despite the hype, JPEG files are still safe as you must have a stripper program running on your system in order to strip the virus file off the image file (see
2004 for another JPEG attack).
On 28 June the Scalper worm was discovered attacking FreeBSD/Apache Web servers. The worm is designed to set up a flood net (stable of zombies which could be used to overwhelm one or more systems).
2003 - Sobig, Slammer, Lovgate, Fizzer, Blaster/Welchia/Mimail Sobig, a worm that carried its own SMTP mail program and used Windows network shares to spread started the year. Sobig variants continued to multiply throughout the year. Slammer, exploiting vulnerabilities in Microsoft's SQL 2000 servers, hit Super Bowl weekend. Its spreading technique worked so well that for some period of time all of South Korea was effectively eliminated from the Internet (obscured). It received significant media coverage. The unique entry that February saw was Lovgate. This was unique as it was a combination of a Trojan and a worm; two pieces of malware that generally don't get combined. Starting in early May Fizzer spread via usual E-mail methods but also used the KaZaa peer-to-peer network to spread. While generally not unique types, August is (in)famous for a combination of Sobig.F, Blaster (also known as Lovsan and MSBlast), Welchia (or Nachi), and Mimail; all spreading rapidly through a security vulnerability in a Windows Distributed Component Object Model (DCOM) Remote Procedure Call (RPC) interface. 2003 also saw what appeared to be a use of worm-like techniques used in the spreading of spam. Sobig dropped a component that could later be used by spammers to send mail through infected machines. The social engineering techniques used by virus/worm writers improved dramatically as well. Some of the malware this year was accompanied by very realistic graphics and links in an attempt to make you think the mail actually came from the likes of Microsoft or Paypal.
2004 - Trojan.Xombe, Randex, Bizex, Witty, MP3Concept, Sasser, Mac OS X, W64.Rugrat.3344, Symb/Cabir-A, JS/Scob-A, WCE/Duts-A, W32/Amus-A, WinCE/Brador-A, JPEG Weakness, SH/Renepo-A, Bofra/IFrame, Santy Year 2004 started where 2003 left off with social engineering taking the lead in propagation techniques. Trojan.Xombe was sent out to a wide audience. It posed as a message from Microsoft Windows Update asking you to run the attached revision to XP Service Pack 1. (This, and like messages that "phish" for personal information, are expected to take a lead role in 2004 -- and, yes, phish is the correct term for a message designed to "fish" for personal information; the technique is called phishing.) In February it was demonstrated that virus writers were starting to ply their craft for money. A German magazine managed to buy a list of infected IP addresses from a distributor of the virus Randex. These IP addresses were for sale to spammers who could use the infected machines as mail zombies. The end of February saw Bizex go after ICQ users through an HTML link that downloaded an infected SCM (Sound Compressed Sound Scheme) file. The weekend of 20/21 March introduced Witty, the first worm to attack security software directly (some Internet Security Systems' RealSecure, Proventia and BlackICE versions). The worm was malicious in that it erased portions of the hard drive while sending itself out. A Mac OS X scare in the form of MP3Concept was announced 8 April. Said to be a benign Trojan, MP3Concept turned out to be nothing more than a bad proof-of-concept that never made it into the wild. The end of April saw the Sasser worm which is the first to effectively use the LSASS Windows vulnerability; a vulnerability that allowed the worm to spread via an open FTP port instead of through E-mail (even though Microsoft had already issued a patch for the vulnerability -- yet another example of people not paying attention to operating system security updates). Toward the end of May Apple issued critical patches to OS X when a vulnerability that could spread via E-mail and mal-formed Web pages was found. The vulnerability would allow AppleScript scripts to run unchecked; even to the point of deleting the home directory. The proof-of-concept Worm W64.Rugrat.3344 showed up the end of May. This is claimed to be the first malware that specifically attacks 64-bit Windows files only (it ignores 32-bit and 16-bit files). It was created using IA64 (Intel Architecture) assembly code. In June Symb/Cabir-A appeared to infect Nokia Series 60 mobile phones. The worm is designed to spread to nearby Bluetooth-enabled devices. JS/Scob-A appeared in the last half of June. It was special in that it used Javascript to infect Microsoft's IIS Server HTML files through an unpatched vulnerability. User's visiting infected sites were then infected via a download from a Russian site (which was quickly closed down) using an unpatched vulnerability in the IE browser. Mid-July WCE/Duts-A showed up. This was another crude proof-of-concept virus relating to the PocketPC. The virus writer was apparently trying for attention as this text is in the virus: "This is proof of concept code. Also, i wanted to make avers happy.The situation when Pocket PC antiviruses detect only EICAR file had to end ..." Early September saw W32/Amus-A show up. The only thing that qualified this beast to even be mentioned here was that it uses the Microsoft Speech engine in Windows to read out loud: "hamsi. I am seeing you. Haaaaaaaa. You must come to turkiye. I am cleaning your computer. 5. 4. 3. 2. 1. 0. Gule. Gule." where "Gule" is Turkish for "Bye" and "Hamsi" is a small fish found in the Black Sea. August saw WinCE/Brador-A, a backdoor for PocketPC devices. On 14 September that paragon of virus-free file type, the JPEG image, came under attack. To be accurate, the image file itself is not so much to blame as a Microsoft common .DLL file that processes the image file type and has a buffer overrun error that could allow someone to add malicious code to a JPEG image which can then open holes in an attacked system. Shortly after, some Trojan exploits started to appear. In Mid-October SH/Renepo-A showed up on Macintosh OS X systems. This is a shell script worm that installs itself to /System/Library/StartupItems and other sites and can make files on the system vulnerable to further exploitation. Bofra/IFrame made history over the 20/21 November weekend by becoming the first malware to be placed into Internet ads. It is a MyDoom variant that made its way into AdSolution ad serving software. A hacker broke into the system and inserted the malware into served ads until it was noticed and shut down after about 12 hours. Just before Christmas the Santy worm showed up. The unique thing about this beast was that it used Google to find its victims. The worm used a phpBB vulnerability to deface vulnerable sites running that popular bulletin board software and queried Google to find the sites. The worm was of no danger to users of the sites; it just defaced the sites.
2005 - Bropia, Troj/BankAsh, Commwarrior, Chod, PSPBrick, DSTahen, MSIL/Idonus, Troj/Stinx-E In 2005 the end of January saw the Bropia Worm which targets MSN Messenger for spreading. A bit later the "F" version of this worm became popular because of the sexy.jpg file that spread with it. The 9th of February then saw Troj/BankAsh, the first Trojan to attack the new (still in beta) Microsoft AntiSpyware product. This Trojan also was reported to go after various British on-line banking services. The start of March saw distribution of another mobile phone worm: Commwarrior, which spread via MMS messaging. The end of March/start of April saw variants of Chod appear. This is a sophisticated worm that spreads via E-mail and the MSN Messaging client. Its messages are very close to what a real user would send and, for the first time, attempts to spoof the return address as being from an anti-virus company (Trend or Symantec, and Microsoft, although coming from Microsoft has been a social engineering ploy for some time now). 6 Oct brought the first Playstation Portable Trojan, PSPBrick. This malware does not spread by itself but comes disguised as a MOD for the PSP. When placed on the PSP the MOD erases a number of system files that prevent the PSP from being restarted and basically turns it into a brick; thus the name. And, not to be outdone, on 12 Oct the Trojan DSTahen showed up which basically does the same thing for the Nintendo DS system. Install the Trojan and you end up with a brick. 14 Oct saw MSIL/Idonus which the maker wanted to be the first Vista virus but because it uses NET 2.0 and other systems that can be installed on earlier operating systems it wasn't; but it is unique none-the-less. The 10th of November Troj/Stinx-E Trojan horse appeared with a trick that hid itself beneath the Sony DRM software on systems with that software installed. The DRM software is designed to protect copyrighted audio but, in hiding itself, it provided an opportunity for malware to hide behind that software in the hope to avoid detection. Not something new but just to note that during the year Creative Labs shipped 3,700 Zen MP3 players carrying the Wullik-B virus.
2006 - OSX/Leap-A, OSX/Inqtana.A, Redbrowser.A, Icabdi.A, SubVirt, Bagoly, Yhoo32.explr, Stardust.A, Yamanner.A, W32.Chamb, OSX/Macarena, Grey Goo Attack, iAdware, JS/Quickspace.A The first beast of 2006 that uses a previously unused attack vector appeared mid-February. OSX/Leap-A attacks the Macintosh OS/X system instead of Windows. The worm spreads via the iChat instant messaging system, forwarding itself as a file called LATESTPICS.TGZ to contacts on the infected users' buddy list. The executable inside is disguised by a JPEG image icon to trick people into clicking on the executable file. The very next day (17 Feb) another new Mac worm appeared: OSX/Inqtana.A. This is a proof-of-concept worm that uses a Bluetooth OBEX Push transfer to move between machines. 28 Feb saw Redbrowser.A. While a Trojan, this appears to be the first J2ME (Java 2 Mobile Edition) malware and the first mobile malware that tries to steal money. Initial releases targeted only Russian users. On 7 March Icabdi.A became the first virus to infect a Microsoft Infopath .XSN file. As usual with firsts, this was a proof-of-concept beast that is a Trojan dropper. Mid-March Microsoft, of all people, along with the University of Michigan developed the proof-of-concept SubVirt rootkit. SubVirt would live as a virtualization layer between the hardware and the "real" operating system and present its own operating system to the user; effectively taking over the computer. They developed the software to better understand how to attack their own software in order to better defend it [eWeek article]. On 22 April f-secure announced a proof of concept virus called Bagoly that infects MATLAB m-file source files. The code is prepended to the start of the m-file. Around 19 May a unique Yahoo! IM malware called yhoo32.explr appeared. The unique thing this beast does is to install its own Web browser (called "Safety Browser") which has an icon that looks like IE. This browser takes people to sites that load the system with other malware. The end of May a proof of concept macro virus called Stardust.A appeared. The unique thing about this macro virus was that it was directed toward attacking StarOffice/OpenOffice documents instead of Word documents. This is the first known attack on this alternate office suite. The 12th of June the Yamanner.A Javascript worm appeared as the first known exploit of the Yahoo! E-mail system. This was a zero-day exploit of the Yahoo! system and the worm spread automatically if you simply opened an infected message using Internet Explorer. No attachment was necessary. August 1st Symantec reported the appearance of W32.Chamb, a proof of concept infector of .CHM help files. 31 October saw the appearance of OSX/Macarena, the first infector of Macintosh OS X Mach-O files. Macarena was able to directly infect the program code and did not need to rely on a resource fork like Leap before it. Around 19 November a bunch of self-replicators appeared in Second Life, the multiplayer game. These were rings scripted with the Linden Scripting Language and, in general, called a Grey Goo attack. Late November saw the introduction of iAdware, the first spyware program for Mac OS X. It was proof-of-concept but indicates some attention is being given to the Macintosh platform. On 2 December there were reports of a Quicktime exploit affecting Myspace profiles. Called JS/Quickspace.A, the infected MOV file contains Javascript that will download a Javascript file which will modify your Myspace profile so that all who visit your Myspace profile will get infected as well. More on that here. Of interest, but maybe not really historic, in November Spybot.ACYR showed up to exploit Symantec's Anti-Virus program. It used a hole discovered and patched some six months earlier but still managed to spread via careless users and other methods built into the malware. The distribution of malware with products continued into 2006 when McDonald's in Japan gave out MP3 players containing the QQpass spyware Trojan and Apple sent out some video iPods with the RavMonE.exe virus on them. Google also distributed some E-mails to the Google Video Blog group containing W32/Kapser.A@mm; a mass mailing worm. Finally, on 29 December an unnamed proof-of-concept exploit against region tags in MMS SMIL which are vulnerable to buffer overflow causing arbitrary code execution was published. The IPAQ 6315 and i-mate PDA2k are affected and it's unknown if patches are available at the time of this writing.
2007 - Agent.BKY, iPod Linux Virus, TI.Tigraa.a, SB.Badbunny, WH/Vred.A, Zhelatin/Storm, IM-Worm:W32/Skipi.A, MSN Trojan March 30th brought an animated cursor vulnerability which, two days later, was exploited by the Trojan downloader worm Agent.BKY. This beast infects HTML and other similar files and these, when viewed, download other malicious software. April 5th brought the announcement of a proof-of-concept (very buggy and unnamed) virus for the iPod; specifically for the iPod Linux operating system. On 29 May Viruslist.com posted the proof of concept TI.Tigraa.a memory resident 492 byte Trojan for the TI-89 graphing calculator line. It won't spread but introduces another device to malware. SB.Badbunny was reported out by Symantec on 7 June. The thing that makes this beast interesting is the fact that it's spreads over multiple operating systems (including the Macintosh) using multiple languages (JavaScript on Windows, Ruby on the Mac, and Python on Linux) and OpenOffice macros while it attempts to spread via Instant Messaging. The middle of June F-Secure announced WH/Vred.A which is a proof-of-concept virus infecting WinHex scripts; the first to do so. While not new, the social engineering of the Zhelatin/Storm Trojan series was quite effective. As an example, in August the gang started sending messages indicating the receiver had applied to various sites and their temporary login name/password were included along with a link. At the link the well-designed page said a sign-in applet had to be downloaded. That applet contained the Trojan which then infected the machine. The messages were quite convincing to many. September saw the introduction of a Skype worm called IM-Worm:W32/Skipi.A. It spread via Skype's instant messaging and pointed people to what looked like a JPEG image but, instead, was a page with a malicious automatic download and just an image from a standard Windows screensaver. October saw a number of Trojan exploits of a PDF vulnerability. While a patch was available for the vulnerability, many were affected because they did not update their PDF reading software and Microsoft delayed getting a Windows patch out. November 18th a new MSN IM Trojan surfaced which was unique in its scan for VNC (Virtual Network Computing) instances. In December a Trojan that hijacks Google ads on Web pages was report. One example would be Trojan.Qhost.WU. The Trojan is not on the Website but, instead, on your computer and intercepts requests for Google ads and serves ads from other sources where the Trojan writer can get the income. It's also possible the sites directed to will also contain malware to further infect your computer.
- In computers, a virus is a program or programming code that replicates by being copied or initiating its copying to another program, computer boot sector or document. Viruses can be transmitted as attachments to an e-mail note or in a downloaded file, or be present on a diskette or CD. The immediate source of the e-mail note, downloaded file, or diskette you've received is usually unaware that it contains a virus. Some viruses wreak their effect as soon as their code is executed; other viruses lie dormant until circumstances cause their code to be executed by the computer. Some viruses are benign or playful in intent and effect ("Happy Birthday, Ludwig!") and some can be quite harmful, erasing data or causing your hard disk to require reformatting. A virus that replicates itself by resending itself as an e-mail attachment or as part of a network message is known as a worm. Generally, there are three main classes of viruses: File infectors. Some file infector viruses attach themselves to program files, usually selected .COM or .EXE files. Some can infect any program for which execution is requested, including .SYS, .OVL, .PRG, and .MNU files. When the program is loaded, the virus is loaded as well. Other file infector viruses arrive as wholly-contained programs or scripts sent as an attachment to an e-mail note. System or boot-record infectors. These viruses infect executable code found in certain system areas on a disk. They attach to the DOS bootsector on diskettes or the Master Boot Record on hard disks. A typical scenario (familiar to the author) is to receive a diskette from an innocent source that contains a boot disk virus. When your operating system is running, files on the diskette can be read without triggering the boot disk virus. However, if you leave the diskette in the drive, and then turn the computer off or reload the operating system, the computer will look first in your A drive, find the diskette with its boot disk virus, load it, and make it temporarily impossible to use your hard disk. (Allow several days for recovery.) This is why you should make sure you have a bootable floppy. Macro viruses. These are among the most common viruses, and they tend to do the least damage. Macro viruses infect your Microsoft Word application and typically insert unwanted words or phrases. The best protection against a virus is to know the origin of each program or file you load into your computer or open from your e-mail program. Since this is difficult, you can buy anti-virus software that can screen e-mail attachments and also check all of your files periodically and remove any viruses that are found. From time to time, you may get an e-mail message warning of a new virus. Unless the warning is from a source you recognize, chances are good that the warning is a virus hoax. The computer virus, of course, gets its name from the biological virus. The word itself comes from a Latin word meaning slimy liquid or poison.
First electronic computer (1943) : the building of Colossus By designing a huge machine now generally regarded as the world's first programmable electronic computer, the then Post Office Research Branch played a crucial but secret role in helping to win the Second World War. The purpose of Colossus was to decipher messages that came in on a German cipher machine, called the Lorenz SZ. The original Colossus used a vast array of telephone exchange parts together with 1,500 electronic valves and was the size of a small room, weighing around a ton. This 'string and sealing wax affair' could process 5,000 characters a second to run through the many millions of possible settings for the code wheels on the Lorenz system in hours - rather than weeks. Both machines were designed and constructed by a Post Office Research team headed by Tommy Flowers at Dollis Hill and transported to the secret code-breaking centre at Bletchley Park, near Milton Keynes, where it was demonstrated on December 8, 1943. We have to fast forward nearly thirty years to 1972 for the arrival of the first desktop all-in-one computer, which are more familar to us today. That honour falls to the HP9830. But unfortunately few people got to hear about it because Hewlett Packard marketed it primarily to scientists and engineers - by nature very quiet people! Colossus (1941) : inside the machine During the Second World War the Germans used a Lorenz encoding teleprinter to transmit their high-command radio messages. The teleprinter used something called the 5-bit Baudot code, which enciphered the original text by adding to it successively two characters before transmission. The same two characters were applied to the received text at the other end to reveal the original message. Gilbert Vernam had developed this scheme in America, using two synchronised tapes to generate the additional random characters. Lorenz replaced the tapes with mechanical gearing - so it wasn't a genuinely random sequence - just extremely complex. But in August 1941 the Germans made a bad mistake. A tired operator sent almost the same message again, using the same wheel settings. It meant the British were able to calculate the logical structure inside the Lorenz. Colossus was then built to find the Lorenz wheel settings used for each message, using a large electronic programmable logic calculator, driven by up to 2,500 thermionic valves. The computer was fast, even by today's standards. It could break the combination in about two hours - the same as today's modern Pentium PC. Colossus Mk II (1944) : a bigger better Colossus Without the contribution of the codebreaking activity, in which Colossus played such a major part, the Second World War would have lasted considerably longer. By the time of the Allied invasion of France in the early summer of 1944, a Colossus Mk II (using nearly twice as many valves to power it) was almost ready. The head of the Post Office Research Team, Tommy Flowers, had been told that Colossus Mk II had to be ready by June 1944 or it would not be of any use. He was not told the reason for the deadline, but realising that it was significant he ensured that the new version was ready for June 1, five days before D-Day. It was in the build-up to D-Day and during the European campaign that followed that Colossus proved most valuable, since it was able to track in detail communications between Hitler and his field commanders. Top secret : the ultimate Chinese walls Colossus weighed around 35 tonnes in Mark II form. Its 2,500 valves, consuming 4.5 Kwatts, were spread over two banks of racks 7 feet 6 inches high by 16 feet wide spaced 6 feet apart. Thus the whole machine was around 80 feet long and 40 feet wide. This huge machine was also one of the most closely guarded secrets of the war yet required dozens of people to build, many of them outside the military establishment in the Post Office. Tommy Flowers was one of the very few entrusted with the overall plan - and even he didn't know the full details of the German codes. In order to ensure security, Colossus was broken down into modules - each given to a separate Post Office team at Dollis Hill. The teams were kept apart - each having no idea of the overall shape of the ground breaking machines they were creating. The building of SIGSALY (1943) : pioneer digital telephone system Another secret wartime computer whose existence was finally revealed many years later was SIGSALY - the secret 'scrambling' system devised to protect the security of high level Allied telephone traffic. SIGSALY - originally codenamed Project X - was also known as 'Green Hornet'. It was the first unbreakable speech coding system, using digital cryptography techniques, with one time digital keys being supplied by synchronised gramophone discs. SIGSALY was built in the USA, though using pulse code modulation (PCM) digital encoding techniques invented in 1937 by the English engineer Alec Reeves. The first priority was to protect the hotline between the Cabinet War Room bunker under Downing Street and the White House in Washington D.C. The 50-ton London terminal was shipped over in 1943 and housed in the basement of the Selfridges annexe in Oxford Street, under tight guard.
Compiler, in computer science, computer program that translates source code, instructions in a program written by a software engineer, into object code, those same instructions written in a language the computer’s central processing unit (CPU) can read and interpret. Software engineers write source code using high level programming languages that people can understand. Computers cannot directly execute source code, but need a compiler to translate these instructions into a low level language called machine code.
Compilers collect and reorganize (compile) all the instructions in a given set of source code to produce object code. Object code is often the same as or similar to a computer’s machine code. If the object code is the same as the machine language, the computer can run the program immediately after the compiler produces its translation. If the object code is not in machine language, other programs—such as assemblers, binders, linkers, and loaders—finish the translation.
Most programming languages—such as C, C++, and Fortran—use compilers, but some—such as BASIC and LISP—use interpreters. An interpreter analyzes and executes each line of source code one-by-one. Interpreters produce initial results faster than compilers, but the source code must be re-interpreted with every use and interpreted languages are usually not as sophisticated as compiled languages.
Most computer languages use different versions of compilers for different types of computers or operating systems, so one language may have different compilers for personal computers (PC) and Apple Macintosh computers. Many different manufacturers often produce versions of the same programming language, so compilers for a language may vary between manufacturers.
The print head in these types of printers sprays drops of liquid ink onto the page. Ink jet and bubble jet printers have good image quality and are fast; however, printouts have a tendency to smear if they get wet.
Laser: These work in a manner similar to a photocopier. A roller is charged with electricity, and a laser is used to remove the charge from portions of the roller. Powdered ink (toner) sticks to the parts of the roller that were hit by the laser and is transferred from the roller to the paper. Then the ink is baked into the paper using a heater. Laser printers produce very high quality output and are very fast.
Dot-matrix (impact): In a dot-matrix printer, a print head moves across the page. Characters or graphics are created by using a cluster of pins. These pins press an inked ribbon to the paper to create a dot. Each character or image is made out of a series of dots. These printers are usually cheap and durable, so they are still used by many businesses as invoice printers. They tend to be slow and noisy, and the output quality is the lowest of all types of printers.
Dye diffusion thermal transfer: Also known as thermal dye sublimation, dye sub, or thermal dye transfer, this is a process used by color printers. A colored wax film or crayon is moved across the page. The pigment is heated and deposited on the page. The paper frequently goes through the printer four times, one time for each color.
This article describes the 4 gigabyte (GB) random access memory (RAM) Tuning feature and the Physical Address Extension (PAE) switch.
MORE INFORMATION The /3GB and /PAE switches in the Boot.ini file are to be used with the following products:
• Microsoft Windows 2000 Advanced Server • Microsoft Windows 2000 Datacenter Server • Microsoft Windows Server 2003, Enterprise Edition • Microsoft Windows Server 2003, Datacenter Edition
When the /3GB switch is used with Windows 2000 Professional or with Windows 2000 Server, the kernel components are loaded into the memory space by using the 4 GB RAM Tuning feature in the same way as they load in Windows 2000 Advanced Server and in Windows 2000 Datacenter Server. This functionality lets device-driver developers test their drivers in this configuration without having to install Windows 2000 Advanced Server or Windows 2000 Datacenter Server. The user-mode memory space is still limited to 2 GB.
When the /3GB switch is used with Windows XP Professional, with Windows Server 2003, Datacenter Edition, with Windows Server 2003, Enterprise Edition, the /3GB switch works identically across versions. This functionality lets device-driver developers test their drivers in this configuration without having to install one of the Windows Server 2003 products just listed. The user-mode memory space is now limited to 3 GB.
Caution Microsoft supports using the /3GB switch in Windows Server 2003, Standard Edition in a production environment for use by Active Directory. For other applications, Microsoft supports using the /3GB switch in Windows Server 2003, Standard Edition only in a production environment if the application vendor has tested in this environment and if the vendor is willing to support the customer who is using this functionality. Microsoft Exchange Server 2003 and Microsoft SQL Server 2000 are supported in production using this functionality. Contact your application vendor regarding their application. The /3GB switch can cause some applications to have problems that are related to address dependencies or to a reduction in kernel space. Except in the cases described here, the /3GB switch in Windows Server 2003, Standard Edition is only for development and testing purposes.
Note: The /3GB switch can lead to resource starvation of Active Directory when you enable it on an Exchange server. The /PAE switch lets developers perform similar testing of device drivers by forwarding 64-bit addresses to kernel-mode components. This feature is known as Physical Address Extension (PAE), and it may not work on all chip sets. Any addresses that are over 32 bits are guaranteed to work by using the /nolowmem switch from the Boot.ini file that discards the lower 4 GB of memory.
IMPORTANT: These configurations are not supported on Windows 2000 Professional and Windows 2000 Server. These configurations are only made available for testing purposes. Do not use these switches in a production environment unless you are using one of the products in the bulleted list at the top of this section.
In these products, the 4 GB RAM Tuning feature enables a 3 GB area of user-mode memory for programs to use. This feature can expand the virtual address range for user-mode memory from 0x0000000 through 0xBFFFFFF (the user-mode address range is typically from 0x0000000 through 0x7FFFFFFF). The range of memory that is available for kernel-mode components shrinks from 0x80000000-0xFFFFFFFF to 0xC0000000-0xFFFFFFFF. We do not recommend using this feature in Windows Server 2003, Standard Edition in a production environment.
Using the /3GB switch from the Boot.ini file with Windows 2000 Professional or with Windows 2000 Server can give the appearance of a 3 GB range of user-mode memory. However, the memory from 0x80000000 through 0xBFFFFFFF is not usable. Because kernel-mode components are now limited to using from 0xC0000000 through 0xFFFFFFF memory range, developers can test kernel-mode components.
When I first heard that AMD had plans to extend the x86 ISA to 64 bits, I thought it was a terrible idea. Though x86 is the world's most successful ISA, it's also the world's most widely disparaged. Programmers, analysts, architecture buffs, and enthusiasts often see x86 as a leaden albatross around the neck of the entire computing industry, and like the Mariner's albatross we were all hoping it would just fall off at some point and slip quietly into the deep. But in spite of such hopes, I really knew better. In fact, I've argued elsewhere that x86 isn't going away anytime soon, and it no longer makes any real sense to gripe about its quirks from a performance perspective. I won't recap that argument here, but I can sum it up briefly.
Most of us would probably assent to the following statement: "there's a huge global market for mainstream business and consumer software, and the overwhelming majority of that software just so happens to use the x86 ISA." This statement is true, as far as it goes, but framing x86's role in the software industry this way misses an important point. In my article "The Future of x86 and the Concept of the ISA," I argue that a statement like the following would provide a more relevant assessment of the true state of the software industry: "There's a huge global market for mainstream business and consumer x86 software, and several smaller markets for software written to other ISAs." All discussions of the desktop prospects of widely ported operating systems (i.e. Linux) or of the possible effects of greater open source market penetration aside, this statement should still ring true to anyone who's acquainted with the present realities of the installed base of IT and consumer software.
If we think realistically about most of the world's commercial software not as "software" in the abstract but as x86 binary code, then it becomes apparent that improvements to the x86 ISA represent one of the most practical and cost-effective ways to advance and expand the x86 software market. Indeed, Intel's continuing extensions of additions to the x86 ISA prove just this point. Consider the move from 16 bits to 32 bits, the addition of the x87 floating-point instructions, and the addition of integer and then floating-point SIMD instructions. All of these modifications of x86 helped bring new capabilities to the PC, allowing it to find new applications and enter new markets. Thus, the ongoing adaptation of the x86 ISA to ever newer technological contexts has been one of the essential subplots in the past two decades' story of the "information revolution." The present article outlines what AMD hopes is the next step in x86's evolution: x86-64. As we'll see, x86-64 is more than just a 64-bit extension to the 32-bit x86 ISA; it adds some new features, as well, while getting rid of some obsolete ones. Note that this article deals with the x86-64 ISA only. The sequel will cover the specific implementations (Hammer, Opteron, etc.). And note also that the general discussions of 64-bit computing that make up the first half of the article are applicable to 64-bit platforms, not just x86-64. So those of you interested in the implications of a possible Apple move to a 64-bit platform like the PPC 970 might want to read at least the first half of the article. Why 64 bits? The question of why we need 64-bit computing is often asked but rarely answered in a satisfactory manner. That this is so is evidenced by the fact that the question keeps coming up again and again in online discussions of AMD's upcoming Hammer processor. There are good reasons for the confusion surrounding the question, the first of which is the rarely acknowledged fact that "the 64-bit question" is actually two questions: 1) how does the existing 64-bit server and workstation market use 64-bit computing, and 2) what use would the consumer market have for 64-bit computing. People who ask the 64-bit question are usually asking for the answer to question 1 in order to deduce the answer to question 2. This being the case, we'll first look at question 1 before tackling question 2. What is 64-bit computing? If you've read my introduction to the basic concepts in microprocessor technology, "Understanding the Microprocessor," then you're familiar with the code/data distinction and its implications. (If you haven't read that article, you might want to at least skim it and look at the diagrams before going any further.) Simply put, the labels "16-bit," "32-bit" or "64-bit," when applied to a microprocessor, characterize the processor's data stream. Although you may have heard the term "64-bit code," this designates code that operates on 64-bit data. In more specific terms, the labels "64-bit," 32-bit," etc. designate the number of bits that each of the processor's general-purpose registers (GPRs) can hold. So when someone uses the term "64-bit processor," what they mean is "a processor with GPRs that store 64-bit numbers." And in the same vein, a "64-bit instruction" is an instruction that operates on 64-bit numbers.
In the diagram above, I've tried my best to modify an older diagram in order to make my point. A quick recap, in case you don't remember the original diagram: black boxes are code, white boxes are data, and gray boxes are results. Also, don't take the instruction and code "sizes" too literally, since they're intended to convey a general feel for what it means to "widen" a processor from 32 bits to 64 bits. You should notice that not all of the data in either memory, the cache, or the registers is 64-bit data. Rather, the data sizes are mixed, with 64 bits being the widest. We'll discuss why this is and what it means, shortly. (I should've made the outgoing data stream on the 64-bit processor a mix of 64-bit and 32-bit data, but it would've been too much work to go in and change all of those boxes like that. As it is, I just used the resize function the whole batch and left it at that.) Note that in the 64-bit CPU pictured above, the width of the code stream has not changed; the same-sized opcode could theoretically represent an instruction that operates on 32-bit numbers or an instruction that operates on 64-bit numbers, depending on what the opcode's default data size is. (Fore more on opcodes, see this page. We'll talk about the specifics of x86-64 opcodes in the next section.) On the other hand, the width of the data stream has doubled. In order to accommodate the wider data stream, the sizes of the processor's registers and the sizes of the internal data paths that feed those registers must be doubled. Now let's take a look at two programming models, one for a 32-bit processor and another for a 64-bit processor.
The registers in the 64-bit CPU pictured above are twice as wide as those in the 32-bit CPU, but the size of the instruction register (IR) that holds the currently executing instruction is the same in both processors. Again, the data stream has doubled in size, but the instruction stream has not. Finally, you might also also note that the program counter (PC) is doubled in size. We'll talk about the reason for this, shortly. Now, what I just told you above was the simple answer to the question, What is 64-bit computing? If we take into account the fact that the data stream is made up of multiple types of data--a fact hinted at in the first comparative diagram above--then the answer gets a bit more complicated. For the simple processor pictured above, the two types of data that it can process are integer data and address data. Ultimately, addresses are really just integers that designate a memory address, so address data is just a special type of integer data. Hence, both data types are stored in the GPRs, and both integer and address calculations are done by the ALU.
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