========
Newsgroups: alt.comp.virus
Subject: Frequently Asked Questions 2/4
From: harley@europa.lif.icnet.uk (David Harley)
Date: 22 Mar 1996 16:02:35 GMT


               alt.comp.virus (Frequently Asked Questions) 
               *******************************************
                           
                       Version 1.01c : Part 2 of 4
                      Last-modified 21st March 1996


                    ("`-''-/").___..--''"`-._
                     `6_ 6  )   `-.  (     ).`-.__.`)
                     (_Y_.)'  ._   )  `._ `. ``-..-'
                   _..`--'_..-_/  /--'_.' ,'
                  (il),-''  (li),'  ((!.-'



ADMINISTRIVIA
=============
	
Disclaimer
----------

This document is an honest attempt to help individuals with computer
virus-related problems and queries. It can *not* be regarded as being
in any sense authoritative, and has no legal standing. The authors
accept no responsibility for errors or omissions, or for any ill effects
resulting from the use of any information contained in this document.

Not all the views expressed in this document are mine, and those views
which *are* mine are not necessarily shared by my employer.

Copyright Notice
----------------

Copyright on all contributions to this FAQ remains with the authors
and all rights are reserved. It may, however, be freely distributed 
and quoted - accurately, and with due credit. B-)

It may not be reproduced for profit or distributed in part or as
a whole with any product for which a charge is made, except with 
the prior permission of the copyright holders. To obtain such permission,
please contact the maintainer of the FAQ.


	David Harley 
	************

--------------------------------------------------------------------

TABLE OF CONTENTS
=================

	Part 1
        ------

	(1)	I have a virus - what do I do?
	(2)	Minimal glossary
	(3)	What is a virus (Trojan, Worm)? 
	(4)	How do viruses work?
	(5)	How do viruses spread?
	(6)	How can I avoid infection?
	(7)	How does antivirus software work? 

----->	Part 2
	------

----->	(8)  	What's the best anti-virus software 
	  		(and where do I get it)?
----->	(9)	Where can I get further information?
----->	(10) 	Does anyone know about 
		* Mac viruses?
		* UNIX viruses?
		* macro viruses?
		* the AOLGold virus?
		* the PKZip trojan?
		* the xyz PC virus?
----->	(11)	Is it true that...?
----->	(12)	Favourite myths
		* DOS file attributes protect executable files from
                  infection
		* I'm safe from viruses because I don't use bulletin
		  boards/shareware/Public Domain software
		* FDISK /MBR fixes boot sector viruses
		* Write-protecting suspect floppies stops infection
		* The write-protect tab always stops a disk write
		* I can infect my system by running DIR on an infected
		  disk

        Part 3
	------

	(13) What are the legal implications of computer viruses?

	Part 4
	------

	(14)	Miscellaneous

        Are there anti-virus packages which check zipped files?
        What's the genb/genp virus?
        Where do I get VCL and an assembler, & what's the password?
        Send me a virus.
        Is it viruses, virii or what?
        Where is alt.comp.virus archived?
        What about firewalls?
        Viruses on CD-ROM.
        Removing viruses.
        Can't viruses sometimes be useful?
        Do I have a virus, and how do I know?
        What should be on a (clean) boot disk?
        What other tools might I need?
        What are rescue disks?
        Are there CMOS viruses?
        How do I know I'm FTP-ing 'good' software?
        What is 386SPART.PAR?
        Can I get a virus to test my antivirus package with?
        When I do DIR | MORE I see a couple of files with funny names...
	Reasons NOT to use FDISK /MBR
        Placeholders

-------------------------------------------------------------------

(8) What's the best antivirus software (and where do I get it)?
===============================================================

In case it's not absolutely clear from the following, I can't 
possibly answer the first part of this question! There are, 
however, some suggestions following for sources of software
and of information on particular packages, comparative reviews etc.
The danger of this approach is that sites, servers, and packages
come and go, and I haven't time to keep track of all these 
variables. Some of these URLs have been passed on by trusted
sources, but I haven't the time to check them all out regularly.
If you run into problems, please let me know (by e-mail, please).

Most of the people who post here have their favourites: if you just
ask which is the best, you'll generally get either a subjective
"I like such and such", recommendation of a particular product by
someone who works for that company, or a request to be more specific
about your needs. Some of us who are heavily involved with virus
control favour using more than one package and keeping track of the
market. Don't trust anything you read in the non-technical press.
Don't accept uncritically reviews in the computing press, either:
even highly-regarded IT specialists often have little understanding
of virus issues, and many journalists are specialists only in
skimming and misinterpreting. Magazines like Virus Bulletin and
Secure Computing are much better informed and do frequent comparative
reviews, and are also informative about their testing criteria,
procedures and virus suites. Recently, a number of articles have been
posted here by people who've run their own tests on various packages.
These are often of interest, but should not be accepted uncritically.
(No-one's opinion should be accepted uncritically!)

Valid testing of antivirus software requires a lot of care and
thought, and not all those who undertake it have the resources,
knowledge or experience to do it properly.

You may get a more informed response if you specify what sort of system
you have - DOS, Windows, Win95? XT, AT, 386 or better? Is the system
networked, and are you asking about protecting the whole network?
(What sort of network?) Are you running NT, OS/2 or Win95, any of which
involve special considerations?  Be aware that there is more than one way
of judging the effectiveness of a package - the sheer number of viruses
detected; speed; tendency to false alarms; size (can you run it from a
single floppy when necessary?); types of virus detection & prevention
(not at all the same thing) offered (command-line scanning, TSR scanning,
behaviour blocking, checksumming, access-control, integrity shell etc.);
technical support etc.

DOS packages available from SimTel etc. include

        F-Prot
        AVP Lite
        McAfee
        TBAV

Most Shareware/Freeware packages can be obtained from SimTel via
anonymous FTP or WWW, e.g.

http://www.coast.net/SimTel/msdos/virus
ftp://ftp.coast.net/SimTel/msdos/virus/

Mirror sites include:

USA:-
        ftp.cdrom.com
        uiarchive.cso.uiuc.edu
        oak.oakland.edu
        wuarchive.wustl.edu
        ftp.uoknor.edu
        ftp.pht.com

UK:-
        micros.hensa.ac.uk
        src.doc.ic.ac.uk
        ftp.demon.co.uk

as well as other sites in many other parts of the world.

Of course, such products can often be obtained direct from the
publisher's WWW or FTP sites too.

There is a shareware program for Win95 called the Doctor, for which
I can't at present find the co-ordinates. [GC points out
that they have an area on Compuserve (GO NCSAVIRUS): GW has found an
elderly copy at

        http://www.tucows.com/files/doc9509.zip

Also, McAfee and Thunderbyte have Win95 programs.

ftp://ftp.mcafee.com/pub/antivirus/
http://thunderbyte.com/ftp/thunderbyte/
ftp://ftp.thunderbyte.com/

ChekMate is described by its author as a targeted integrity checker.
It's a potentially useful shareware supplement to a good virus scanner.

  Via anonymous ftp at:
        ftp.coast.net/SimTel/msdos/virus/cm200.zip
        ftp.demon.co.uk/pub/simtel/msdos/virus/cm200.zip
        ftp.demon.co.uk/antivirus/ibmpc/av-progs/cm200.zip
        gate.net/pub/users/ris1/cm200.zip

  At the World-Wide Web site:
        http://www.valleynet.com/~joe/avdos.html


Commercial
----------

[vendors are invited to supply full contact details and indicate the range
of platforms their product range covers. Let's not overdo the hype, though,
guys.]

There is a pretty comprehensive list of anti-virus developers at 

	http://www.virusbtn.com/AVLinks/

(NB Some of the following, though not shareware, can be obtained for 
evaluation via anon FTP or WWW.

Please note, I have not tested or even seen all the packages listed 
here, or all the contact data, come to that, and listing here does not 
imply recommendation (though I won't list anything I *know* is 
rubbish....).

DSAVTK (Dr Solomon's Anti-Virus ToolKit)
[DOS; DOS & Windows; DOS & Win95; NetWare; NT; OS/2; Unix; Mac]

UK Support: support@uk.drsolomon.com
US Support: support@us.drsolomon.com
UK Tel: +44 (0)1296 318700
USA Tel: +1 617-273-7400
CompuServe: GO DRSOLOMON
Web: http://www.drsolomon.com
FTP: ftp://ftp.drsolomon.com
Evaluation copy of Findvirus Dos scanner available via the Web.

*************

F-Prot Pro (DOS, Windows 3.x, Win95, WinNT, NetWare)

There are two flavours, though I gather that Command Software and
Data Fellows are currently doing joint development.

Command Software Systems Inc.
1+407-575 3200
ftp://ftp.commandcom.com

Data Fellows Ltd.
f-prot@DataFellows.com
ftp://ftp.DataFellows.com
http://www.DataFellows.com
http://www.Europe.DataFellows.com

UK:

Portcullis (for Data Fellows) 44-181-868-0098

Command Software UK 44-171-259-5710
command@command.co.uk

More details inc. in ORDER-2.DOC, supplied with the shareware version.

************

IBM AntiVirus:
http://www.brs.ibm.com/ibmav.html
800-551-3579 (US only)
800-465-7999
fax: 800-267-5185

************

McAfee Associates
2710 Walsh Ave
Santa Clara, CA  95051
95054-3107  USA
Voice (408) 988-3832
FAX   (408) 970-9727
BBS   (408) 988-4004
CompuServe ID: 76702,1714 or GO MCAFEE
mcafee@netcom.com
ftp://ftp.mcafee.com/pub/antivirus/
http://www.mcafee.com/
[DOS, Windows, Win95, NetWare]

************

NAV (Norton AntiVirus)  [DOS, Windows, Win95, Mac]
http://www.symantec.com/ ftp://ftp.symantec.com
US Support:  541-465-8420                            AOL:  SYMANTEC
European Support:  31-71-353-111        Australian Support:  61-2-879-6577

************

AVP LITE
ftp:            ftp.command-hq.com
sub-directory:  pub/command/avp
file:           avplite.zip

************

Sweep   http://www.sophos.com/ ftp://ftp.sophos.com

************

Thunderbyte http://thunderbyte.com/ftp/thunderbyte/software/
            ftp://ftp.thunderbyte.com (?)

************

Invircible ftp://ftp.invircible.com
           ftp://ftp.datasrv.co.il/pub/usr/netz/
           http://invircible.com/

************


Reflex Magnetics Ltd
31-33 Priory Park Road
London
NW6 7UP
United Kingdom

Tel+44 (0)171 372 6666 
Fax+44 (0)171 372 2507 
BBS+44 (0)171372 2584 
Emailsales@reflex-magnetics.co.uk 

http://www.reflex-magnetics.co.uk/

************

Reflex Magnetics Ireland

Unit 24 Johnstown Industrial Centre, Waterford, Ireland.
tel: +353-(0)51-841051 J fax: +353-(0)51-841052 

http://www.iol.ie/~ralf/

************

NH&A                         
577 Isham St. # 2-B          
New York, NY 10034   
Phone:  212-304-9660         
Fax:  212-304-9759
CompuServe: 72115,661
Internet: nhirsch@nha.com
URL: http://www.nha.com
BBS:  212-304-9759,,,,,,,3

************

Microsoft (Macro Virus fixes) - http://www.microsoft.com
For updates to MSAV, contact Symantec (but better to get a more
up-to-date package). CPAV updates from the same source.

There is a paper by Yisrael Radai which documents many of the problems
with MSAV.

   ftp://ftp.informatik.uni-hamburg.de/pub/virus/texts/viruses/msaveval.zip

************

ViruSafe, ViruSafe-95

I believe a version of this program was at one time marketed by
Xtree.

They also maintain a Virus Hot Line via their WWW site or 
E-mail (virus@eliashim.co.il).

-------------------------------------------------------------
EliaShim, LTD.                  Computer Security Specialists
5 Haganim st. Haifa 35022                 Tel: +972-4-8516111
ISRAEL                                    Fax: +972-4-8528613
Email: shimon@eliashim.co.il              BBS: +972-4-8516113
URL: http://www.eliashim.com
-------------------------------------------------------------


----------------------------------------------------------------------------

VirusNet PC (DOS, Win3.x, Win95) - (File: VNPC.EXE)
VirusNet LAN (DOS, Win3.x, Win95, All Networks) - (File: VNLAN.EXE)
StopLight PC (DOS, Win3.x) - (File: SLELS.EXE)
StopLight for Win95 (Win95, Win3.x, DOS) - (File: Check Site)
StopLight for OS/2 (OS/2, Dual Boot to DOS and Win3.x) - (File: sltmos2.exe)

Safetynet, Inc.
140 Mountain Ave.
Springfield, NJ 07081
201-467-1024 (Sales and Support)
800-OS2-SAFE (Sales and Support in US and Canada)
201-467-1611 (Fax)
201-467-1581 (BBS 28800,n,8,1)
Web: http://www.safe.net/safety/
FTP: ftp.safe.net /pub/safetynet/
EMail: support@safe.net
CompuServe: GO CIS:SAFE

AntiVirus and security software evals and product updates are available from
the Safetynet Web, FTP, BBS and CompuServe sites.

*****************

MIMESweeper (Mail scanning 'firewall')

Integralis Ltd.
10 Brewery Court
Theale
Berkshire
RG7 5AH
+44(0) 1734 306060
Fax +44(0) 1734 302143
info@integralis.co.uk

-----------------------------------------------------------------------------


There is a comprehensive set of product reviews at:

        http://www.first.org/virus/virrevws/

and a number of reputable vendors include comparative reviews,
papers on testing etc. on their WWW/FTP servers.

Virus Bulletin comparative reviews are available from 

	http://www.virusbtn.com/Comparatives/

and information is also available on their testing protocols.

There are links to just about every anti-virus site you ever heard of at

        http://www.innet.net/~ewillems/

In the event of a *real* tragedy, there are a number of firms which
specialize in data recovery. In the UK, there are S&S International
(see above) and Ontrack Data Recovery Europe (0800-243996). In the
US, there's Ontrack Computer Systems (parent company of Ontrack
...Europe). I believe Maxtor also offer a service of this sort,
but I have no details at present.

Ontrack Data Recovery, Inc.
6321 Bury Drive, Suites 13-21
Eden Prairie, MN  55346
Phone: 612-937-5161
FAX: 612-937-5750
BBS: 612-937-0860
Toll free:
Minnesota office:  1-800-872-2599
California office:  1-800-752-7557
Washington, DC:  1-800-650-2410
Japan: 0120-413-374 (Japan only)
     International:  (0429)32-6365
UK office: 0800 24 39 96 (UK only)
     From Germany: 0130 815 198
     From France: 05 90 72 42
     International: +44(0)181 974 5522

Compuserve: GO DATARECOVERY
W3: http:\\www.ontrack.com
Email: sales@ontrack.com




(9) Where can I get further information?
========================================

[I haven't checked all these: please mail me if you find any errors]

ftp://ftp.informatik.uni-hamburg.de/pub/virus/texts/catalog/
ftp://ftp.informatik.uni-hamburg.de/pub/virus/texts/carobase/
ftp://ftp.informatik.uni-hamburg.de/pub/virus/texts/viruses/

ftp://ftp.uu.net/pub/security/virus/



http://all.net:8000/cgi-bin/all-search-2
Virus Text Search
 Search engine to check out documents in the following archives:
 VIRUS-L Forum, 40Hex Archives, Risks Forum, Privacy Forum, CERT Advisories,
 Internet RFCs, State Computer Crime Laws, The Telecom Privacy Digest,
 CIAC Advisories, Firewalls Digest.


 http://www-iwi.unisg.ch/~sambucci/icaro/texts
 http://lipsmac.acs.unt.edu/Virus/virinfo.html
 http://www.valleynet.com/~joe/avinfo.html
 http://www.primenet.com/~mwest/av.htm
 http://csrc.ncsl.nist.gov/virus
 http://www.jumbo.com/home/dos/virus
 http://www.valleynet.com/~joe/top10.html
 ftp://ftp.uu.net/pub/virus/progs/virlab15.zip
 http://www.infi.net/~wtnewton/vinfo/master.html

Virus-List Archive (you can also pick up the mk. II FAQ from here):

	ftp://corsa.ucr.edu/pub/virus-l/

Virus Bulletin Home Page - vendor contact info, comparative reviews,
review protocol info etc.

	http://www.virusbtn.com 

S&S International: evaluation copy of FindVirus, product info, virus
encyclopaedia on-line, papers, links to other sites etc.

	http://www.drsolomon.com/
	ftp://ftp.drsolomon.com/

ftp://ftp.sophos.com/
http://www.sophos.com/
Dr.Solomon's History of PC Viruses:
http://dbweb.agora.stm.it/webforum/virus/solomhis.htm
Robert Slade's Virus History:
http://dbweb.agora.stm.it/webforum/virus/sladehis.htm

http://www.innet.net/~ewillems/

http://www.thenet.ch/metro/

Nic Ferri has an expansive home page w. many useful links

	http://www.agora.stm.it/htbin/wwx?fi^N.Ferri

(if that fails, I've had better luck with the one below)

	http://www.agora.stm.it/N.Ferri/antivir.htm

Henri Delger's home page has useful info and links

	http://pages.prodigy.com/X/W/A/XWWC29A

http://www.DataFellows.com/
http://www.Europe.DataFellows.com/

VSUM (not highly-rated for its accuracy)
(Try SimTel mirrors, McAfee sites)

Tom Simondi has written a freeware virus tutorial (VTUTOR10.ZIP).
Unfortunately, I haven't been able to download it so far.

	http://ourworld.compuserve.com/homepages/ck

The WildList (List of viruses currently 'in the wild'
maintained by Joe Wells - doesn't include much description)

ftp://ftp.ncsa.com/pub/virus/wildlist
http://www.drsolomon.com/
http://www.symantec.com/virus/wl.html
http://www.innet.net/~ewillems/vwild.htm

AV Software Update Auto-Notification:
 http://www.primenet.com/~Emwest/up-form.htm

Most anti-virus packages include some information on common
viruses, too.

Virus Descriptions
------------------

 Dr Solomon's Virus Encyclopedia:
 http://www.drsolomon.com/virus/enc/enc.htm
 free-form searches from the datafellows F-Prot virus description database:
 http://www.datafellows.fi/virsearc/query.htm

Virus demonstrations
--------------------

 ftp://ftp.uu.net/pub/virus/progs/virsim1.zip

(I haven't checked this one out yet).
 
 AVP also includes some virus demonstrations, and I know that other
 publishers have demos available. 

 There are also virus simulators, which are not quite the same thing.
 These are sometimes advocated as a means of testing antivirus packages,
 but there are dangers to this approach: after all, a package which
 detects one of these simulators as the virus it detects is, technically,
 false-alarming.

See section F6 of the Mark 2 Virus-L FAQ, which is rather good on 
types and uses of virus simulation.

Books which may be of use:

	Robert Slade's Guide to Computer Viruses - Springer-Verlag
		Pretty good introduction & general resource.
	Computers Under Attack (ed. Denning) - Addison-Wesley
		Aging, but some classic texts
	Survivors' Guide to Computer Viruses (ed. Lammer) - Virus Bulletin
		Uneven, but includes useful stuff from Virus Bulletin
	Dr. Solomon's Virus Encyclopaedia
		You may from time to time find copies of an older edition
		of this in bookshops, though it's better known as part of 
		Dr. Solomon's AntiVirus ToolKit. It's a pretty good guide
		to some of the older viruses. 
	A Short Course on Computer Viruses (F. Cohen) - Wiley
		By the man who 'invented' the concept of computer viruses.
		Some aspects are controversial, but a good introduction to
		his work.

The comp.virus FAQ includes pointers to some books.

Useful (but expensive) periodicals:

	Virus Bulletin

		Virus Bulletin Ltd
		21 The Quadrant
		Abingdon
		Oxfordshire
		OX14 3YS

		44 (0) 1234 555139
		Compuserve 100070,1340


	Computers and Security 

		Elsevier Advanced Technology
		PO Box 150
		Kidlington
		Oxford
		OX5 1AS

		44 (0) 1865-843666
		a.verhoeven@elsevier.co.uk


Rather cheaper (though still expensive for the non-corporate 
non-specialist in security) is the magazine Secure Computing.
West Coast are launching a corporate licence scheme which may 
be of interest to corporate users

	Secure Computing

		West Coast Publishing Ltd.
		William Knox House
		Britannic Way
		Llandarcy
		Swansea
		SA10 6EL
		UK

		44 (0) 1792 324000
		Compuserve 70007,5406


Doubts have been expressed concerning the impartiality or otherwise
of Virus Bulletin, which is a sister company to Sophos, who market
Sweep and other antivirus/security products. VB uses an advisory board
of anti-virus experts from a wide variety of vendors and other
organisations, and its virus statistics are collated monthly from a
variety of sources, not only from Sophos.

Secure Computing, though formerly associated with S&S International, who 
market Dr.Solomon's AntiVirus ToolKit and other security products, is
now an independent organization. SC also has input from experts associated 
with various vendors and other organisations.


***************************************************************************
* As a regular and reasonably knowledgeable reader of both publications,  *
* I'm personally satisfied that neither displays editorial bias, nor do   *
* I believe that either publication intentionally weights its methodology *
* to the unfair advantage of an affiliated product [DH]                   *
***************************************************************************

(10) Does anyone know about... 
==============================

...Mac viruses? 
---------------

The best single source of information on Mac viruses is the online
help included in the freeware package Disinfectant, which can be
obtained from

	ftp://ftp.acns.nwu.edu/pub/disinfectant
	CompuServe
	GEnie
	America Online
	Calvacom
	Delphi
	BIX
	sumex-aim.stanford.edu
	rascal.ics.utexas.edu
	comp.binaries.mac


Information on Mac viruses is also available from the AntiVirus Catalog/
CARObase (see above).

I've also noticed some Mac info at Symantec's web site (www.symantec.com).

Disinfectant is an excellent anti-virus package: however, it doesn't catch
much in the way of hypercard infectors or trojans, nor does it detect
Word 6 macro viruses.

For other mac packages, try Info-Mac mirrors like:

	ftp://ftp.ucs.ubc.ca/pub/mac/info-mac/vir/

The University of Texas holds the latest versions of Disinfectant and 
Gatekeeper, and some documentation on Mac viruses.

	http://wwwhost.ots.utexas.edu/mac/pub-mac-virus.html

Commercial packages include SAM (Symantec) and Virex. Dr. Solomon's
AntiVirus ToolKit for Macintosh is about to be released. 

...UNIX viruses?
----------------

In general, there are virtually no non-experimental UNIX viruses.
There have been a few Worm incidents, most notably the Morris Worm
(a.k.a. the Internet Worm) of 1988.

There are products which scan some Unix systems for PC viruses, 
though any machine used as a file server (Novell, Unix etc.) can be 
scanned for PC viruses by a DOS scanner if it can be mounted as a 
logical drive on a PC running appropriate network client software
such as PC-NFS. 
 
Intel-based PCs running Unix (e.g. Linux, 386BSD, SCO Unix etc.) 
can also be infected by a DOS boot-sector virus if booted from an
infected disk. The same goes for other PC-hosted operating systems
such as NetWare.

While viruses are not a major risk on Unix platforms, integrity
checkers and audit packages are frequently used by system administrators 
to detect file changes made by other kinds of attack. However, Unix
security is outside the scope of this FAQ (see comp.security.unix).

[See also the comp.virus FAQ]

A possibly useful book: 

	Practical Unix Security (Garfinkel, Spafford) - O'Reilly

...macro viruses?
-----------------

Macro viruses spread from files in applications which use
macros capable of being infected, and are limited to the
specific applications for which they were written.

The macro viruses which are receiving attention currently
are specific to Word 6/WordBasic and Excel: however, many
applications, not all of them Windows applications, have
potentially damaging and/or infective macro capabilities
too.

One, now widespread, infects macros attached to Word
6.0 for Windows, Word 6.0.1 for Macintosh, Word 6.0 for
Windows NT, and Word for Windows 95 documents.

What makes such a virus possible is that the macros
are created by WordBASIC, a program language which links
features used in Word to macros, and even allows DOS
commands to be run.

This virus, named "Concept," has no destructive
payload; it merely spreads, after a document containing the
virus is opened, copying itself to other documents as they
are saved, without affecting the contents of documents.
However, other macro viruses have been discovered, and some
of them contain destructive routines.

Microsoft suggests opening files without macros, to
prevent macro viruses from spreading, unless the user can
verify that the macros contained in the document will not
cause damage.  (This does NOT work for all macro viruses.)

For further info on macro viruses, you might like to try

	http://www.drsolomon.com/
	http://www.datafellows.com/macrovir.htm

Richard Martin is working on an FAQ on this subject.

	ftp.gate.net/pub/users/ris1/word.faq

or mail to 

	Bd326@TorFree.Net

	Subject: PLEASE SEND FAQ

...The AOLgold virus
--------------------

This is actually a trojan. The following is extracted from the CIAC
bulletin (Number G-03).

Apparently, an e-mail message is being circulated that contains an attached
archive file named AOLGOLD.ZIP.  A README file that is in the archive
describes it as a new and improved interface for the AOL online service.
Note that there is no such program as AOLGOLD.  Also, simply reading an
e-mail message or even downloading an included file will not do damage to
your machine.  You must execute (or run) the downloaded file to release
the Trojan and have it cause damage.

If you unzip the archive, you get two files: INSTALL.EXE and README.TXT.
The README.TXT file again describes AOLGOLD as a new and improved interface
to the AOL online service.  The INSTALL.EXE program is a self-extracting ZIP
archive.  When you run the install program, it extracts 18 files onto your
hard drive.

The Trojan program is started by running the INSTALL.BAT file.  The
INSTALL.BAT file is a simple batch file that renames the VIDEO.DRV file to
VIRUS.BAT and then runs it.  VIDEO.DRV is an amateurish DOS batch file that
starts deleting the contents of several critical directories on your C:
drive.

When the batch file completes, it prints a crude message on the screen and
attempts to run a program named DoomDay.EXE.  Bugs in the batch file prevent
the DOOMDAY.EXE program from running.  Other bugs in the file cause it to
delete itself if it is run from any drive but the C: drive.  The programming
style and bugs in the batch file indicates that the Trojan writer appears
to have little programming experience.

You can get this and other CIAC notices from the CIAC Computer Security
Archive.

   World Wide Web:      http://ciac.llnl.gov/
   Anonymous FTP:       ciac.llnl.gov (128.115.19.53)

...the PKZip Trojan?
--------------------

There have been at least two attempts to pass off Trojans as an upgrade
to PKZip, the widely used file compression utility. A recent example was 
of the files PKZ300.EXE and PKZ300B.ZIP made available for downloading
from various sources. An earlier Trojan passed itself off as version 2.0.
For this reason, PKWare have never released a version 2.0 of PKZip: 
presumably, if they ever do release another DOS version (unlikely, at
this date, in my opinion), it will not be numbered version 3.0(0).

To the best of my knowledge, the latest version of PKZip is 2.04g.

...xyz PC virus?
----------------

There are several thousand known PC viruses, and the number 'in the 
wild' is in the hundreds. It is not practical to include information 
about all of these in this FAQ. However, information about some or 
most of those which regularly get asked about may shortly (Real Soon
Now) be available in a separate document. Meanwhile, sources of 
information on specific viruses are included in the preceding sections.

There are rarely enquiries about viruses on other computing platforms 
raised in alt.comp.virus, but there is some information concerning 
viruses on most platforms available at the Virus Test Center in Hamburg.

ftp://ftp.informatik.uni-hamburg.de/pub/virus/texts/catalog/
ftp://ftp.informatik.uni-hamburg.de/pub/virus/texts/carobase/

The following sites also have virus descriptions listed alphabetically:

http://www.DataFellows.com/
http://www.drsolomon.com

(11) Is it true that....? 
=========================

  (*or* some favourite hoaxes...)

(1) There is *no* Good Times virus that trashes your hard disk
    and launches your CPU into an nth-complexity binary loop when
    you read mail with "Good Times" in the Subject: field.

 You can get a copy of Les Jones' FAQ on the Good Times Hoax from:

  Via FTP:

  ftp://usit.net/pub/lesjones/good-times-virus-hoax-faq.txt
  ftp://members.aol.com/macfaq/good-times-virus-hoax-faq.txt

  On the World Wide Web:

  http://www.tcp.co.uk/tcp/good-times/index.html
  http://www.singnet.com.sg/staff/lorna/Virus
  http://www.nsm.smcm.edu/News/GTHoax.html

There's a Mini-FAQ available as:

  ftp://usit.net/pub/lesjones/Good-Times-Virus-Hoax-Mini-FAQ.txt

    There *is* at least one file virus christened Good Times
    by the individual who posted it in an attempt to cause 
    confusion. It is more commonly referred to as GT-spoof.

(2) There is no modem virus that spreads via an undocumented
    subcarrier - whatever that means....

(3) Any file virus can be transmitted as an E-mail attachment.
    However, the virus code has to be executed before it actually
    infects. Sensibly configured mailers don't usually allow this
    by default and without prompting, but certainly some mailers
    can support this: for instance, cc:mail can, it seems, launch
    attachments straight into AmiPro. 

[further information on this or other potentially dangerous 
associations would be gratefully received]

    There's room for a lot of discussion here. The jury is still
    out on web browsers: Netscape can certainly be set up to do
    things I don't approve of, such as opening a Word document in
    Word without asking.

    Microsoft have made available a Word viewer which reads Word
    files, but doesn't run attached macros. If possible, use this
    instead.

    The term 'ANSI bomb' usually refers to a mail message or other 
    text file that takes advantage of an 'enhancement' to the MS-DOS 
    ANSI.SYS driver which allows keys to be redefined with an 
    escape sequence, in this case to echo some potentially 
    destructive command to the console. In fact, few systems
    nowadays run programs which need ANSI terminal emulation to run, 
    and there's no guarantee that the program reading the file would 
    pass such an escape sequence unfiltered to the console anyway.
    There are plenty of PD or shareware alternatives to ANSI.SYS that
    don't support keyboard redefinition, or allow it to be turned off. 

    The term mail bomb is usually applied to the intentional 
    bombardment of an e-mail address with multiple copies of a
    (frequently abusive) message, rather than to the above.

    See SimTel/keyboard on sites carrying a SimTel mirror.

(4) There is no known way in which a virus could sensibly be spread
    by a graphics file such as a JPEG or .GIF file, which does not 
    contain executable code. Macro viruses work because the files to 
    which they are attached are not 'pure' data files. 

(5) In general, software cannot physically damage hardware - this
    includes viruses. There is a possibility that specific hardware
    may be damaged by specific code: however, a virus which drops
    a particular payload on the offchance that it's running on a
    system with a particular type of obsolete video card seems more
    than usually futile.


(12) Favourite myths
====================

* DOS file attributes protect executable files from infection

  File attributes are set by software, and can therefore be
  changed by software, including viruses. Many viruses reset a
  ReadOnly/System/Hidden file to Read/Write, infect it, and 
  often reset it to the original attributes afterwards.

  This also applies to other software mechanisms such as
  simulating hardware write-protection on a hard disk.

  However, file protection rights in NetWare *can* help to
  contain virus infections, if set up properly, as can 
  trustee rights. [Trustee assignments govern whether an 
  individual user has right of access to a subdirectory: the 
  Inherited Rights Mask governs the protection rights of 
  individual files and (sub)directories.] 

  Basically, a file virus has the same rights of access as the
  user who happens to inadvertantly activate it.

  Setting up these levels of security is really a function 
  of the network Administrator, but you might like to check 
  (politely) that yours is not only reassuringly paranoid but 
  also knowledgeable about viruses as well as networks, since a
  LAN which is not, in this respect, securely configured, can 
  result in very rapid infection and reinfection of files
  across the whole LAN. In particular, accounts with supervisor
  equivalence can, potentially, be the unwitting cause of very
  rapid dissemination of viruses.

  [See also the comp.virus FAQ (version 2) section D]

* I'm safe from viruses because I don't use bulletin boards/shareware/
  Public Domain software.

  Many of the most widely-spread viruses are Boot Sector Infectors,
  which can't normally infect over a serial or network connection. 
  Writers of shareware, freeware etc. are no more prone to accidental
  infection than commercial publishers, and possibly less. The only
  'safe' PC is still in it's original wrapping (which doesn't mean
  it isn't already infected...) And don't forget that shrinkwrapped
  software may have been rewrapped.

* FDISK /MBR fixes boot sector viruses.

  The mark II comp.virus FAQ is worth reading on this (see Part 1
  of this FAQ).

  In brief, don't use FDISK /MBR *unless* you're *very* sure of what 
  you're doing, as you may lose data. Note also that if you set up the 
  drive with a disk manager such as EZDrive, you won't be able to access 
  the drive until and unless you can reinstall it.

******************************************************************

(i) What does FDISK /MBR do?
    ------------------------

  It places "clean" partition code onto the partition of your hard disk.
  It does **not change the partition information, however.  The /MBR
  command-line switch is not officially documented and was introduced in
  DOS 5.0

[It does sometimes, and when it does it us usually fatal (for the
common user, anyway). FDISK /MBR will wipe the partition table data if
the last two bytes of the MBR are not 55 AA.]

(ii) What is the partition?
     ----------------------

  The partition sector is the first sector on a hard disk.  It contains
  information about the disk such as the number of sectors in each
  partition, where the DOS partition starts, plus a small program. The
  partition sector is also called the "Master Boot Record" (MBR).

  When a PC starts up it reads the partition sector and executes the
  code it finds there.  Viruses that use the partition sector modify
  this code.

  Since the partition sector is not part of the normal data storage
  part of a disk, utilities such as DEBUG will not allow access to it.

[Unless one assembles into memory]

  Floppy disks do not have a partition sector.

  FDISK /MBR will change the code in a hard disk partition sector.


(iii) What is a boot sector?
      ----------------------

  The boot sector is the first sector on a floppy disk.  On a hard disk
  it is the first sector of a partition. It contains information about
  the disk or partition, such as the number of sectors, plus a small
  program.

  When the PC starts up it attempts to read the boot sector of a disk in
  drive A:.  If this fails because there is no disk it reads the boot
  sector of drive C:.  A boot sector virus replaces this sector with its
  own code and usually moves the original elsewhere on the disk.

  Even a non-bootable floppy disk has executable code in its boot sector.
  This displays the "not bootable" message when the computer attempts to
  boot from the disk.  Therefore, non-bootable floppies can still contain
  a virus and infect a PC if it is inserted in drive A: when the PC
  starts up.

  FDISK /MBR will not change the code in a hard disk boot sector.  Most
  boot sector viruses infect the partition sector of hard disks and
  floppy disk boot sectors: most do not infect the boot sector of a hard
  disk - Form virus is an exception.

(iv) How can I remove a virus from my hard disk's partition sector?
     --------------------------------------------------------------

  There are two main alternatives: run an anti-virus product, or use
  FDISK /MBR.

  Most effective anti-virus products will be able to remove a virus from
  a partition sector, but some have difficulties under certain
  circumstances.  In these cases the user may decide to use FDISK /MBR.

  Unless you know precisely what you are doing this is unwise.  You may
  lose access to the data on your hard disk if the infection was done by 
  a virus such as Monkey or OneHalf.

(v) Won't formatting the hard disk help?
    ------------------------------------

  No.  Formatting the hard disk can result in everything being wiped
  from the drive *apart* from the virus.  Format leaves the partition
  sector untouched.  There is always a better way of removing a
  virus infection than formatting the hard disk. 

[Clarification: FORMAT alters the DOS partition, but leaves the
*partition sector*, aka MBR, alone.]

******************************************************************

* Write protecting suspect floppies stops infection. 

This sounds so silly I hesitate to include it. I've never seen it said
on a.c.v., but I've heard it so often in other contexts, I've included
it anyway. Write-protecting a suspect floppy will only protect that
diskette from *re-infection*, if it's already infected. It won't stop
an infected floppy from infecting other (write-enabled) drives.

If you boot with a disk in drive A which is infected with a boot-sector
virus, the fact that the diskette is write-protected will make no
difference at all.

Write-protecting a *clean* floppy will indeed prevent it from being
infected (but see below!).

* The write protect tab always stops a disk write 

Briefly, write protection is built into the hardware on the Mac and 
on the PC (and most other systems, of course, but we can't cover 
everything), and can't be circumvented in software.

However, it is possible for the hardware to fail: it's not common, 
but it happens. Thus when I do a cleanup, I try to create a file on a 
sacrificial floppy before risking my R/O boot disk. Sometimes, I
even remember....

Other caveats: a disk which you receive write-protected could have 
been de-protected, infected, and re-protected. Even a 3.5" disk with 
the write-enable tab removed can be written to by covering the hole 
with (e.g.) masking tape. And, of course, shrink-wrapped software 
could have been infected before the duplication process.

* I can infect my system by running DIR on an infected disk

If you have a clean PC system, you can't contract a boot sector virus
*or* a file virus just by listing the files on an infected floppy.
Of course, if your PC is infected, you may well infect a *clean* floppy
by using 

	DIR A:

It *is* possible to have a scanner report a virus in memory after a
DIR of a floppy with an infected boot sector. The distinction here is
that the virus is *not* actually loaded into memory, so the PC has
*not* been infected.

-----------------------------------------------------------------------

End of a.c.v. FAQ part 2


