The Hacker's Encyclopedia 1998

home *** CD-ROM | disk | FTP | other *** search

/ The Hacker's Encyclopedia 1998 / hackers_encyclopedia.iso / hacking / systems / pchacfaq.txt < prev next >

Wrap

Text File | 2003-06-11 | 25.5 KB | 633 lines

The PC Hacking FAQ ==------------------== Version 1.1 3/14/96 ---------------------------------------------------------------- Written By Olcay Cirit, <olcay@libtech.com> ---------------------------------------------------------------- DISCLAIMER: The author of this text disclaims all liability whatsoever regarding the use and/or misuse of the techniques outlined here or any damages incurred directly or indirectly thereof. Table of Contents -=-=-=-=-=-=-=-=-=-=- X. Introduction 1. Hardware and Firmware a. The BIOS Passwords Resetting System Settings b. Floppy Locks Picking Them Buying them c. Last Resorts Hard Disk Extraction 2. DOS, Windows, and Netware a. Getting access to DOS Boot from a floppy disk Bypass startup files Break out of Autoexec.bat b. Getting Past Windows Screen Savers Password Protection DOS Using Write DOS Using Word DOS through MODE c. Getting Past Netware Common Account Names Resetting Netware 3. Building a SECURE system a. Understanding the Issues Potential "Hackers" Physical Security Software Security Passwords ---------------------------------------------------------------- X. Introduction This FAQ describes how to break-in to a PC (IBM-Compatible) from the outside in, and how to bypass most software-based security measures. The last section details how to secure your PC against such attacks. Hi's and Ho's go out to: KORO the Great, Neil Chou, John Lundgren and those really cool Netware Hackers! [Part 2c (Getting past Netware) is based on parts of the Netware Hacking FAQ!] Why did I write this? Because there were just so many questions on alt.2600 concerning 'How do I get past XXXXX security?' that I got tired of answering each one individually. Expect to see this FAQ expand as I find more bugs and holes in security software. Many of these solutions assume you have physical access to the PC. For example, you can't extract the hard disk or reset the BIOS over a network, but you can do it if you have access to the computer. This FAQ is not written to help computer thiefs, but rather it is intended to increase awareness of backdoors and inefficiencies in security programs. I DO NOT CONDONE SCREWING UP OTHER PEOPLES' COMPUTERS AT ALL!!!!!! Maybe after reading this you won't trust the non-existent security offered by Windows 95 as much. I would like to note that few of these tricks are new. I simply rounded up everything that I could find and what I could glean from personal experience into an organized file. If you have any questions or comments, feel free to contact me. Also, expect to see a version of this for the Macintosh, sometime... :) Have Phun, Olcay Cirit, <olcay@libtech.com> a.k.a, Deep Thought ---------------------------------------------------------------- 1. Hardware and Firmware 1a. The BIOS The BIOS, short for Basic Input/Output Services, is the control program of the PC. It is responsible for starting up your computer, transferring control of the system to your operating system, and for handling other low-level functions, such as disk access. NOTE that the BIOS is not a software program, insofar as it is not purged from memory when you turn off the computer. It's firmware, which is basically software on a chip. :) A convenient little feature that most BIOS manufacturers include is a startup password. This prevents access to the system until you enter the correct password. If you can get access to the system after the password has been entered, then there are numerous software-based BIOS password extractors available from your local H/P/A/V site. :) If not, then there is only one way to get past the BIOS password. It involves discharging the static memory (CMOS) used to store the password and other system information. Once it is discharged, however, you have to reset all the system settings by hand. ****Follow these steps: 1. Start up the computer a. If the system allows it, enter the Setup Screen (Usually by pressing F1, DEL or INS during the memory check) b. Record all the Setup Information. Double Check. 4. Turn off the computer 5. Remove the casing, and put the computer on the ground in such a way that you can see and access the side of the motherboard with the processor on it. 6. Look at the motherboard. a. If you can see a round, disc-like battery, then remove it, and let the computer sit without the battery for 15-30 minutes. Put the battery back in. b. If you have access to the circuit diagrams for the motherboard, look in them for the password or CMOS jumper. Flip it on and off. 9. Replace the computer casing. 10. Enter the Setup Screen, and set the Setup Information back to the original values that you (hopefully) recorded. If you were unable to record this info, then you'll just have to set it up manually. Again, I would like to mention that there are numerous password extractors available for free off the internet and on BBSes. Try those first. They are much cleaner and easier-to-use. ---------------------------------------------------------------- 1b. Floppy Locks Floppy Locks are generally cheap plastic inserts that hook on to the inside of the drive and lock it, thereby preventing you from using the floppy drive. The locks used are usually those little swivel locks used in computer casings to lock the keyboard. If the lock is the swivel type, you can either pick it, or buy a key (they're all the same). To pick it, you'll need a *thin* flathead screwdriver or a paperclip. To pick the lock, take the paperclip and insert it into the little notch on the inside of the swivel lock. Now, pull to the opposite side of the lock until the swivel is in the unlocked position. If you choose to buy a key, you can: A. Go to your local computer service center, and buy one of these keys. (Very cheap. Often less than $0.75) B. Buy the same brand of floppy lock, and use the key that comes with it. ---------------------------------------------------------------- 1c. Last Resorts If you are *REALLY* desperate to break-in to this PC, then the following *might* work: 1. Remove the PC Casing 2. Extract the hard disk (By unscrewing and disconnecting) 3. Transfer it to another computer. (Make sure that it is NOT set as the boot drive.) 4. Start up this computer, and access the hard disk from there. This will probably not work if an encrypted file system is in use. The only way to access such disks is to enter the password, or figure out a way to decrypt it, so if you forget your password, you're hosed. :( ---------------------------------------------------------------- 2. DOS, Windows, and Netware 2a. Getting access to DOS With some systems, they are set up to boot directly to some sort of shell/security program, like Windows, or Windows 95. If you want to get access to a DOS prompt, you have some choices: A. Boot from a floppy disk B. Bypass startup files C. Break out of Autoexec.bat ***Booting from a floppy requires you to create a system disk. You can do this using the DOS command FORMAT /S which will format a disk and place system files on it. Also, the Windows format has an option allowing you to create a system floppy. Before you create a system disk, you must determine which floppy drive is used to boot. If the system has both a 1.2MB (5.25") Floppy Drive and a 1.44MB (3.5") Drive, it is likely that the boot drive is the 1.2 MB floppy drive. If the computer has only one floppy drive, it is quite safe to assume that it is the boot drive. However, if you are unsure as to which drive is the boot drive, you can either find out by entering System Setup (as described in section 1) or by observing which floppy drive is read right before the operating system loads. If the system is set to boot only from the hard disk, then you can refer to Section 1 on how to reset the BIOS. Once you have a system disk, you place it in the floppy drive, and turn on or reset the computer. If you have done everything right, the computer will boot from the floppy drive and you will have access to a DOS prompt. ***Bypassing startup files is quite simple, but only works on versions of DOS 6.0 or better and Windows 95. When you turn on the computer and you see the text: Starting MS-DOS ... or Starting PC-DOS ... or Starting Windows 95 ... Press and hold the SHIFT or F5 key IMMEDIATELY. This will bypass the startup files (CONFIG.SYS and AUTOEXEC.BAT) as long as the system administrator has not disabled this feature. Additionally, you can press and hold F8 when the startup text shows to enter the Boot menu. This lets you selectively disable certain commands, or bypass the startup files totally, among other things. ***Breaking out of AUTOEXEC.BAT is rather simple also. When the computer starts up and the operating system starts loading, press Ctrl+Break (Or Ctrl+C) repeatedly. When the AUTOEXEC.BAT executes, this will terminate it and drop you to DOS. This will work unless the System administrator temporarily disabled the keyboard. ---------------------------------------------------------------- 2b. Getting to DOS from Windows If the above tactics fail, and the machine automatically loads Windows, then you still have a chance of getting to DOS. Windows by default gives you free access to DOS. There are special security programs to prevent the user from accessing DOS. Most of these can be bypassed. Screen Savers ============= The password protection built-in to Windows 3.1 is extremely weak. You can bypass it by simply editing CONTROL.INI and searching for the Password field. Delete the junk that appears after the equal sign. The password protection in Windows 95 is much stronger, but you can still bypass it by *carefully* moving or renaming all .PWL files in the C:\Windows directory. Password Protection =================== Q: Windows starts up, and you are presented with yet another password dialog box. What do I do? A: **If this is the Primary Windows Logon or a Network logon, then you can usually get past it by pressing the Cancel button (No Joke!). This is because the Logon information is used primarily for desktop preferences and remote file sharing. **If this is a third-party security program, such as the one built-in to After Dark, try pressing Ctrl+Alt+Del when the dialog is presented to you. Most security programs go out of their way to be secure, and Windows 3.1 interprets this as not responding to the system, and thus will allow you close it. Windows 95 pops up a neat little dialog box that lets you terminate any running application. How convenient. :) Once you subvert this, you can prevent it from bothering you again by editing the LOAD= and RUN= sections in C:\WINDOWS\WIN.INI. Q: Windows starts up, and program manager loads, but the File menu is disabled, and so is DOS and File Manager. How can I access DOS??? A: There are many Security programs for Windows (3.1 *AND* 95) that do this, and other things. There are a few ways around them: **Try this first: DOS through Write ================= 1. Go into Accessories, and start up Write (or Wordpad) NOT, I REPEAT NOT, NOTEPAD!! 2. Open C:\COMMAND.COM 3. A little dialog box will pop up. Select NO CONVERSION 4. Select Save As... 5. Save it as C:\WINDOWS\WINHELP.EXE 6. If it asks if you want to overwrite WINHELP.EXE, choose YES 7. Press F1. Normally, this loads Windows Help, but now it will create a DOS prompt window. **Try this next: DOS through Word ================ 1. If they have Microsoft Word installed, start it up. 2. From the Tools Menu, select Macro. 3. Type in a Macro name, and click "Create" 4. When the Macro window comes up, type in one of the following depending on which Windows you are using: For Windows 3.1: Shell Environ$("COMSPEC") For Windows 95: Shell Environ$("COMMAND") For Windows NT: Shell Environ$("CMD") If all else fails: Shell "C:\COMMAND.COM" 5. Run the macro by pressing the little play button on the macro toolbar. This will launch a DOS prompt. **If you're using Windows 95, try this: DOS through MODE ================ When Windows 95 Shuts Down and shows that dumb graphic, it's really just sitting on top of DOS. You can actually issue DOS commands (although the graphic will cover them) on the system after shutdown!! A simple way to do this is to type: CLS After the graphic shows. However, the text will be in 40-column mode, which is hard to read, and incompatible with some programs. If you want to get a nice, clean DOS prompt, you can type: MODE CO80 This will reset the screen display to normal (80-column, 16 color) mode. Since *MOST* Windows Security programs are based on a VxD, they will be unloaded (along with Windows) after shutdown, leaving you free to explore using DOS. ---------------------------------------------------------------- 2c. Getting past NetWare This section is based on excerpts from the Netware Hacking FAQ. Common Account Names ==================== Novell Netware has the following default accounts: SUPERVISOR, GUEST, and Netware 4.x has ADMIN and USER_TEMPLATE as well. All of these have no password set. Only a dummy would leave the SUPERVISOR and ADMIN accounts unprotected, so you might as well not try. However, many administrators will create special-purpose accounts that have easy-to-guess names, some with no password at all. Here are a few of the common ones and their typical purposes: Account Purpose ------- --------------------------------------------------- POST Attaching to a second server for email MAIL PRINT Attaching to a second server for printing LASER HPLASER PRINTER LASERWRITER ROUTER Attaching an email router to the server BACKUP May have password/station restrictions (see below), WANGTEK used for backing up the server to a tape unit attached to the workstation. For complete backups, Supervisor equivalence is required. TEST A test user account for temp use ARCHIVIST Palindrome default account for backup CHEY_ARCHSVR An account for Arcserve to login to the server from from the console for tape backup. Version 5.01g's password was WONDERLAND. GATEWAY Attaching a gateway machine to the server GATE FAX Attaching a dedicated fax modem unit to the network FAXUSER FAXWORKS WINDOWS_PASSTHRU Although not required, per the Microsoft Win95 Resource Kit, Ch. 9 pg. 292 and Ch. 11 pg. 401 you need this for resource sharing without a password. Resetting Netware ================= When NetWare is first installed, the account SUPERVISOR and GUEST are left unprotected, that is, with no password. SUPERVISOR has free run of the system. You can do anything you want. But how can you make the server think it has just been installed without actually reinstalling the server and losing all data on the disk? Simple. You just delete the files that contain the security system! In Netware 2.x, all security information is stored in two files (NET$BIND.SYS and NET$BVAL.SYS). Netware 3.x stores that information in three files (NET$OBJ.SYS, NET$VAL.SYS and NET$PROP.SYS). The all new Netware 4.x system stores all login names and passwords in five different files (PARTITIO.NDS, BLOCK.NDS, ENTRY.NDS, VALUE.NDS and UNINSTAL.NDS [This last file may not be there, don't worry]). Although Novell did a very good job encrypting passwords, they let all directory information easy to find and change if you can access the server's disk directly, using common utilities like Norton's Disk Edit. Using this utility as an example, I'll give a step-by-step procedure to make these files vanish. All you need is a bootable DOS disk, Norton Utilities' Emergency Disk containing the DiskEdit program and some time near the server. 1. Boot the server and go to the DOS prompt. To do this, just let the network boot normally and then use the DOWN and EXIT commands. This procedure does not work on old Netware 2.x servers and in some installations where DOS has been removed from memory. In those cases, you'll have to use a DOS bootable disk. 2. Run Norton's DiskEdit utility from drive A: 3. Select "Tools" in the main menu and then select "Configuration". At the configuration window, uncheck the "Read-Only" checkbox. And be very careful with everything you type after this point. 4. Select "Object" and then "Drive". At the window, select the C: drive and make sure you check the button "physical drive". After that, you'll be looking at your physical disk and you be able to see (and change) everything on it. 5. Select "Tools" and then "Find". Here, you'll enter the name of the file you are trying to find. Use "NET$BIND" for Netware 2, "NET$PROP.SYS" for Netware 3 and "PARTITIO.NDS" for Netware 4. It is possible that you find these strings in a place that is not the Netware directory. If the file names are not all near each other and proportionaly separated by some unreadable codes (at least 32 bytes between them), then you it's not the place we are looking for. In that case, you'll have to keep searching by selecting "Tools" and then "Find again". [In Netware 3.x, you can change all occurences of the bindery files and it should still work okay]) 6. You found the directory and you are ready to change it. Instead of deleting the files, you'll be renaming them. This will avoid problems with the directory structure (like lost FAT chains). Just type "OLD" over the existing "SYS" or "NDS" extension. Be extremely careful and don't change anything else. 7. Select "Tools" and then "Find again". Since Netware store the directory information in two different places, you have to find the other copy and change it the same way. This will again prevent directory structure problems. 8. Exit Norton Disk Edit and boot the server again. If you're running Netware 2 or 3, your server would be already accessible. Just go to any station and log in as user Supervisor. No password will be asked. If you're running Netware 4, there is one last step. 9. Load Netware 4 install utility (just type LOAD INSTALL at the console prompt) and select the options to install the Directory Services. You be prompted for the Admin password while doing this. After that, you may go to any station and log in as user Admin, using the password that you have selected. **NOTE: If Disk Edit is unavailable, any Disk Editing utility with searching capabilities will suffice. ---------------------------------------------------------------- 3. Building a SECURE System 3a. Understanding the Issues Potential "Hackers" =================== After reading this FAQ, you've probably revised your idea of a secure PC quite a bit. Truth be told, IBM didn't design the Personal Computer with security in mind. Back in 1980, their main objective was to get _something_ to market before Apple gobbled up all the market share. After awhile, security programs started to emerge that attempted to bridge this gap. These were quite popular, and were put into use by many companies to prevent 'curious' employees from messing with the computers. However, ways to bypass these security programs were quickly found. As long as computers are designed for convenience, and with humans in mind, this will almost always happen. So, who are potential "Hackers"? The answer is: Anyone. Experienced users especially, but even newbies sometimes find weak spots. This is not to say that everyone *is* a hacker. As always, prevention is the best medicine. The following sections deal with how to secure your system, both through physical and software-based means. Physical Security ================= In the old days, back when computers filled multiple rooms, the security of a system was basically all physical: Locks, security guards, etc. Now the emphasis has shifted away from physical security, and is leaning more towards software-based methods. However, in some cases, a certain degree of physical security is in order. **If you want to prevent people from resetting your BIOS and accessing the floppy drives, etc. you have to secure the system itself. This can be done by having the computer in a locked room, leaving only the screen and keyboard accessible. There are many products which let you extend the reach of screen and keyboard cables. Even some that let you control many different computers using one screen. ***To protect your hard disk data, I would suggest investing in a removable media system that lets you "hot-swap" and lock hard disks. The hard disk could then be easily removed (with the *unique* key) and stored in a safe to prevent theft of data. ***Computer locks which bind your computer to a desk are good for discouraging theft. Software-Based Security ======================= Below is a list of measures you can take to secure your system using software/firmware based methods. They are listed in order of increasing security, so minimum security would be only implementing option #1, maximum security would be implementing #1-8. Keep in mind that implementing any of these without implementing every item below it leaves possible entry points open. 1. Set up a BIOS password for both the Setup screen *and* access to the system. a. Make sure the password is not easily guessable (i.e., birthdate, name backwards, etc. are easily guessed) b. Make sure that the password is the maximum possible number of characters supported by the BIOS. 2. Disable floppy booting from within the BIOS 3. Disable Bypass of startup files a. This is done by adding the line: SWITCHES=/C/K to the CONFIG.SYS file. b. Additionally, you might want to precede all statements in the Autoexec.bat with CTTY NUL, and then have CTTY CON as the last line. This prevents breaking out of autoexec.bat 4. Set up a DOS-based Security TSR a. Make sure you cannot access the floppy drive without a password, and that it allows for write-protection. b. Make sure it allows for password protection. 5. Set up a Windows-Based Security program a. Make sure you can control which features of Windows you can limit or disable. b. Make sure it allows for password protection. 6. Install an encrypted filesystem program. (i.e., CryptDisk) a. This will prevent access to the computer and files on the hard disk unless the password is entered. It will render your data unaccessible even if the hard disk is extracted from the system. Passwords ========= Passwords are generally the weakest link in the security chain. When choosing a password, remember these tips: Do NOT choose something obvious. Swear words, your birthdate, topics pertaining to what you do and/or your interests are are examples of BAD passwords. A Good Password is one that is totally random. To pick a password, try this: Grab a dictionary. Close your eyes, and flip to a random page. With your eyes still closed, put your finger on a random spot on this page. Remember the word, and do this again. Combine the two words, append a three-digit number to the end, and you've just made a very secure password! Also, NEVER write your password down. Keep it in your head. Always.